Gas detector

Abstract

To provide a gas detector capable of accommodating various gas detection methods.SOLUTION: A gas detector includes a main body, a first gas detection module that is separably disposed on the main body, and a second gas detection module that is separably disposed on the main body. The first gas detection module has a first chamber, a first gas sensor that is separably disposed on the first chamber, and a sensor base that is separably disposed on the first gas sensor. Furthermore, the second gas detection module has a second chamber and a second sensor unit that is separably disposed on the second chamber. The connection layout of the first gas detection module with respect to the main body is the same as the connection layout of the second gas detection module with respect to the main body.SELECTED DRAWING: Figure 24

Description

[Technical field]

[0001] The present invention relates to a gas detector for detecting a gas. [Background technology]

[0002] Some gas detectors allow the gas sensor (gas detection module) for detecting gas to be replaced in order to detect multiple types of gas (see Patent Document 1). In addition, some gas detectors are equipped with multiple types of gas sensors, allowing multiple types of gas to be detected simultaneously (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication 2010-218100 [Patent Document 2] Patent Publication No. 2023-076338 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional gas detectors have a structure that allows only interchangeable gas detection modules with an integrated housing that has the same external shape, and therefore have the problem of being unable to accommodate various gas detection methods.

[0005] In view of the above circumstances, the present invention aims to provide a gas detector that can be used with various gas detection methods. [Means for solving the problem]

[0006] The present invention relating to the above object is a gas detector for detecting a gas, comprising: a main body having a main body-side inlet passage through which the gas flows in and a main body-side outlet passage through which the gas flows out; a first gas detection module arranged in a separable state relative to the main body and detecting the gas; and a second gas detection module arranged in a separable state relative to the main body and detecting the gas, wherein the first gas detection module is arranged in a separable state relative to the main body, and comprises a first chamber-side inlet passage detachably connected to the main body-side inlet passage, a first chamber-side outlet passage detachably connected to the main body-side outlet passage, and a first internal space interposed between the first chamber-side inlet passage and the first chamber-side outlet passage, a first gas sensor arranged in a separable state relative to the first chamber, and its gas detection unit comes into contact with the gas passing through the first internal space, a first sensor receiving connector arranged in a separable state relative to the first gas sensor and detachably connected to a first sensor-side connector of the first gas sensor, and a first body receiving connector detachably connected to a main body-side connector of the main body. and a first sensor base electrically connecting the gas sensor and the main body, the second gas detection module being disposed in a state where it can be separated from the main body, and comprising a second chamber having a second chamber side inlet channel detachably connected to the main body side inlet channel, a second chamber side outlet channel detachably connected to the main body side outlet channel, and a second internal space interposed between the second chamber side inlet channel and the second chamber side outlet channel, and a second sensor unit disposed in a state where it can be separated from the second chamber, the second sensor unit of the second gas detection module further comprising a second housing, a second gas sensor disposed inside the second housing and contacted with the gas passing through the second internal space, and a second main body receiving connector disposed in the second housing and detachably connected to a main body connector of the main body,The gas detector is characterized in that the connection layout of the second body-receiving connector to the body is the same.

[0007] In relation to the above gas detector, a shape of a connection interface between the first chamber and the first gas sensor in the first gas detection module and a shape of a connection interface between the second chamber and the second sensor unit in the second gas detection module may be different from each other.

[0008] In relation to the above gas detector, the first chamber may have a first chamber side engaging portion, the first sensor base has a first base side engaging portion that engages with the first chamber side engaging portion, and the first chamber is fixed to the first sensor base by engaging the first chamber side engaging portion with the first base side engaging portion, the second chamber has a second chamber side engaging portion, and the main body has a second main body side engaging portion that engages with the second chamber side engaging portion, and the second chamber is fixed to the main body by engaging the second chamber side engaging portion with the second main body side engaging portion. Effect of the Invention

[0009] According to the present invention, the gas detector can be flexibly adapted to various gas detection methods. [Brief description of the drawings]

[0010] [Figure 1] 1A is a front perspective view of a main body of a gas detector according to a first embodiment, viewed obliquely from above, and FIG. 1B is a rear perspective view of the main body of the gas detector, viewed obliquely from below. [Diagram 2] FIG. 1A is a top view, (B) a front view, (C) a left side view, (D) a right side view, (E) a bottom view, and (F) a rear view of the main body. [Diagram 3] FIG. 2 is a perspective view of the main body with the front cover open. [Figure 4] FIG. 2 is a front view of the main body with the front cover open. [Diagram 5]FIG. 2 is a right side view of the main body with the front cover and right side cover omitted. [Figure 6] FIG. 2 is an exploded perspective view of the pump of the main body. [Figure 7] FIG. 2 is an exploded perspective view of the flow sensor of the main body. [Figure 8] FIG. 2 is a front view of the main body with the pump and flow sensor removed. [Figure 9] 1A is a perspective view seen from behind, FIG. 1B is a right side view, and FIG. 1C is a rear view of a gas detection module of a gas detector according to a first embodiment. [Figure 10] 1A is a perspective view of the gas detection module with the chamber opened, viewed from below the rear, FIG. 1B is a bottom view, and FIG. 1C is a perspective view of the gas sensor disassembled. [Figure 11] FIG. 2A is a right side view of the gas detector with the main body and gas detection module separated, and FIG. 2B is a right side view of the gas detector with the gas inspection module attached to the main body. [Figure 12A] FIG. 2 is a block diagram showing the internal circuit configuration of the gas detector. [Figure 12B] 2 is a block diagram showing the functional configurations of a main body side computer, a base side computer, and a sensor side computer of the gas detector. FIG. [Figure 13A] FIG. 13 is a block diagram showing a modified example of the internal circuit configuration of the gas detector. [Figure 13B] 13 is a block diagram showing a modified example of the functional configuration of the main body side computer, the base side computer, and the sensor side computer of the gas detector. FIG. [Figure 14] 13 is a diagram showing a determination table for determining the type of the gas detection module by the main body computer of the gas detector. FIG. [Figure 15] 4 is a flowchart showing the procedure of a gas detection program for the gas detector. [Figure 16] 13A is a perspective view seen from behind, FIG. 13B is a right side view, and FIG. 13C is a rear view of a gas detection module of a gas detector according to a second embodiment. [Figure 17]1A is a perspective view of the gas detection module with the chamber open, as viewed from below on the rear side, and FIG. 1B is a perspective view of the gas sensor disassembled. [Figure 18] FIG. 2A is a right side view of the gas detector with the main body and gas detection module separated, and FIG. 2B is a right side view of the gas detector with the gas inspection module attached to the main body. [Figure 19] FIG. 2 is a block diagram showing the internal circuit configuration of the gas detector. [Figure 20] 2 is a block diagram showing functional configurations of a main body side computer, a base side computer, a first sensor side computer, and a second sensor side computer of the gas detector. FIG. [Figure 21] 13A is a perspective view of a chamber in a gas detection module of a gas detector of a third embodiment, viewed diagonally from above at the rear, FIG. 13B is a front view, FIG. 13C is a left side view, FIG. [Figure 22] 1A is a front perspective view of a sensor unit in the gas detection module, viewed diagonally from below; FIG. 1B is a rear perspective view of the sensor unit, viewed diagonally from above; FIG. [Diagram 23] 13 is a rear view showing a state in which the sensor unit and the chamber in the gas detection module are connected. FIG. [Figure 24] FIG. 1A is a right side view of the gas detector with the main body, sensor unit, and chamber separated, (B) is a right side view of the gas detector with the chamber attached to the main body, and (C) is a right side view of the gas detector with the sensor unit attached to the main body. [Diagram 25] FIG. 2 is a block diagram showing the internal circuit configuration of the gas detector. [Figure 26] 2 is a block diagram showing the functional configuration of a main body side computer and a unit side computer of the gas detector. FIG. [Figure 27] FIG. 11 is a diagram showing a determination table for determining the type of a gas sensor by a base computer of the gas detector of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] First Embodiment 11, the gas detector 1 of the first embodiment includes a main body 10 and a gas detection module 50. The main body 10 and the gas detection module 50 are detachably connected to each other.

[0013] (Main body housing) 1 and 2, the main body 10 has a front cover 13A, a top cover 13B, a rear cover 13C, a bottom cover 13D, a right side cover 13E, and a left side cover 13F as a housing. In the following description, the direction from the front to the rear in Fig. 1 may be referred to as the "depth direction", the direction from the top to the bottom as the "vertical direction", and the direction from the right side to the left side as the "width direction".

[0014] On the front surface of the front cover 13A, various operation buttons 28A, a display device 28B, and an external communication connector 28C are provided. On the bottom cover 13D, there are an intake port 14IN for taking in atmospheric gas into the main body, and an exhaust port 14OUT for discharging gas sucked in from the intake port 14IN. Furthermore, on the bottom cover 13D, there is a lever 15 protruding downward, which is operated when attaching or detaching the gas detector 1 itself to a stand (not shown).

[0015] 3 and 4, a hinge 13G with a rotation axis extending in the width direction is provided at the boundary between the lower edge of the front cover 13A and the front edge of the bottom cover 13D. This hinge 13G allows the entire front cover 13A to swing toward the front side in the depth direction and toward the lower side in the up-down direction. As a result, the front side of the internal space of the housing of the main body 10 is fully opened. An elastic body 13X is provided on the inner surface of the front cover 13A, which presses the gas detection module 50 toward the rear side when closed.

[0016] (Internal structure of the main body) As shown in FIG. 5, in which the right side cover 13E and the front cover 13A are omitted, the pump 18, the flow sensor 20, the main body inflow path 22, the main body outflow path 24, the main body circuit board 26 (stored in a case), the main body inlet 22IN, and the main body outlet 24OUT are provided inside the main body 10. Note that the "inflow" of the main body inflow path 22 here means the flow from the suction port 14IN to the gas detection unit of the gas detection module 50, and the "outflow" of the main body outlet path 24 means the flow from the gas detection unit of the gas detection module 50 to the exhaust port 14OUT. The main body inflow path 22 is a gas path that directly connects the suction port 14IN and the main body inlet 22IN. The main body outlet path 24 has a first outlet path 24A that connects the main body outlet 24OUT and the flow sensor 20, a second outlet path 24B that connects the flow sensor 20 and the pump 18, and a third outlet path 24C that connects the pump 18 and the exhaust port 14OUT.

[0017] The pump 18 pumps gas in the main body side outflow path 24 in the outflow direction. The pump 18 has an electromagnetic coil 18A fixed to the housing side and a diaphragm pump body 18B driven by the electromagnetic coil 18A. The diaphragm pump body 18B is structured such that a permanent magnet fixed to a rod vibrates due to AC drive of the electromagnetic coil 18A, and a diaphragm fixed to the end of the rod changes the volume inside the casing to pump out gas. As shown in FIG. 6, the diaphragm pump body 18B can be easily removed by pulling it out toward the front. This allows the diaphragm pump body 18B to be quickly replaced by opening the front cover 13A if it breaks down.

[0018] The flow sensor 20 measures the flow rate of gas flowing through the main body side outflow path 24. The flow sensor 20 is electrically connected by a wiring 20A with a connector extending from the main body side circuit board 26. As shown in FIG. 7, the flow sensor 20 is fixed to the housing by a fixing screw 20B extending in the depth direction. Therefore, by removing the wiring 20A and the fixing screw 20B, the flow sensor 20 can be easily removed by pulling it out toward the front in the depth direction. This allows the flow sensor 20 to be quickly replaced by opening the front cover 13A if it breaks down.

[0019] 8 shows the main body 10 with both the diaphragm pump body 18B and the flow sensor 20 removed. An outlet 24Bout of the second outflow path 24B and an inlet 24Cin of the third outflow path 24C open near the electromagnetic coil 18A in the main body 10. When the diaphragm pump body 18B is installed by pushing it in, the outlet 24Bout and the inlet 24Cin are connected to the diaphragm pump body 18B.

[0020] An outlet 24Aout of the first outflow path 24A and an inlet 24Bin of the second outflow path 24B are open on the rear side of the housing from which the flow sensor 20 is removed. When the flow sensor 20 is installed by pushing it in, the outlet 24Aout and the inlet 24Bin are connected to the flow sensor 20.

[0021] Inside the main body 10, from bottom to top, the suction port 14IN and exhaust port 14OUT, the main body side inlet 22IN and main body side outlet 24OUT, the flow sensor 20 (outlet 24Aout and inlet 24Bin), and the pump 18 (outlet 24Bout and inlet 24Cin) are arranged in this order so as to overlap each other in the vertical direction. This makes it possible to configure the main body 10 extremely compact. At the same time, the pump 18 and the flow sensor 20 can be maintained from the front side without removing the main body 10 from the stand.

[0022] 8, the main body circuit board 26 is disposed parallel to the left side cover 13F along the inner plane of the left side cover 13F. The main body circuit board 26 controls the entire gas detector 1. The main body circuit board 26 includes a main power supply circuit (not shown), a main body computer (CPU) 34, a main body memory (not shown), a main body connector 26A, etc. The main body connector 26A is a part of an interface for connecting to the gas detection module 50.

[0023] In addition, a main body side auxiliary board 27 is installed inside the front cover 13A and is electrically connected to the main body side circuit board 26 by a flexible wiring 27A passing near the hinge 13G. As a result, the main body side auxiliary board 27 becomes a part of the main body side circuit board 26. The main body side auxiliary board 27 is electrically connected to various operation buttons 28A, a display device 28B, and an external communication connector 28C provided on the front cover 13A. As shown in FIG. 1, the external communication connector 28C can be exposed to the outside when the front cover 13A is closed. As a result, a communication line of an external computer such as a PC can be connected to the external communication connector 28C when the front cover 13A is closed, so that the various operation buttons 28A can be operated and the display of the display device 28B can be confirmed while communicating with the external computer.

[0024] (Main unit interface to gas detection module) 4, the arrangement of the body-side interface for connecting the main body 10 and the gas detection module 50 is defined by three locations: the body-side connector 26A, the body-side inlet 22IN, and the body-side outlet 24OUT. The body-side connector 26A provides an electrical connection function, and the body-side inlet 22IN and the body-side outlet 24OUT provide a gas connection function.

[0025] <Gas detection module> 9 and 10 show the overall configuration of the gas detection module 50. The gas detection module 50 has a chamber 52, a gas sensor 60, and a sensor base 70.

[0026] (Chamber) The chamber 52 has a chamber-side inlet 52IN of a male structure (protruding structure) detachably connected to the main body-side inlet 22IN of a female structure, a chamber-side outlet 52OUT of a male structure (protruding structure) detachably connected to the main body-side outlet 24OUT of a female structure, and an internal space 54 interposed between the chamber-side inlet 52IN and the chamber-side outlet 52OUT. As shown in Figs. 10(A) and (B) , the internal space 54 is a cylindrical space having a bottom surface, and its annular tip is a sensor insertion port 58. The chamber-side inlet 52IN and the chamber-side outlet 52OUT are connected to the bottom surface of the internal space 54. A rubber seal ring is installed in the sensor insertion port 58. The sensor insertion port 58 (seal ring) is brought into contact with a seal surface 68, which is an annular tapered surface of the gas sensor 60, to make the internal space 54 a closed space. The chamber 52 has a pair of chamber-side engagement parts 55, which are elastic claw structures. The chamber 52 and the sensor base 70 are joined together by engaging the chamber side engaging portion 55 with the base side engaging portion 79, which is a pair of receiving groove structures on the sensor base 70. Since the chamber side engaging portion 55 has an elastic structure, when the user forcibly separates the chamber 52 and the sensor base 70, the engagement between the chamber side engaging portion 55 and the base side engaging portion 79 is released, and they can be separated from each other.

[0027] (Gas sensor) 9(B), the gas sensor 60 has a sensor housing 61, a gas detection unit 62, a sensor-side circuit board 63, a sensor-side computer 64 and a sensor-side memory (not shown) mounted on the sensor-side circuit board 63, and a sensor-side connector 65 mounted on the sensor-side circuit board 63. The sensor-side circuit board 63 provides a path for transmitting power and a path for transmitting and receiving signals.

[0028] The sensor housing 61 has a cylindrical shape, and the end face located at the tip thereof becomes the detection surface of the gas detection unit 62 that comes into contact with the gas in the internal space 54 of the chamber 52. A sealing surface 68 that is an annular tapered surface is formed around the periphery of the sensor housing 61. When the sensor insertion port 58 (seal ring) of the chamber 52 comes into contact with this sealing surface 68, the internal space 54 on the side of the gas detection unit 62 becomes a closed space.

[0029] The gas detector 62 is a part that detects gas using electricity, and various detection methods can be used. For example, a new ceramic method that detects gas using the amount of heat generated when a combustible gas is burned on an ultrafine oxide catalyst (new ceramic), a semiconductor method that detects the change in resistance value that occurs when a metal oxide semiconductor comes into contact with a gas to be detected as a gas concentration, a hot wire semiconductor method that detects the change in resistance value that occurs when a metal oxide semiconductor sintered around a heated precious metal wire coil comes into contact with a gas to be detected as a gas concentration, a thermal conduction method that detects the change in thermal conductivity caused by the gas to be detected as a gas concentration, a constant potential electrolysis method that electrolyzes the gas to be detected on an electrode kept at a constant potential and detects the current generated at that time as a gas concentration, and an infrared method that irradiates infrared rays into a measurement cell (space) and detects the amount of change in infrared rays due to the absorption of the gas to be detected. For example, when the gas detector 62 is a hot wire semiconductor method, a heater part of a precious metal wire coil is built into the gas detector 62. That is, the gas sensor 60 has a common sealing surface 68 of the housing and a common arrangement of the sensor-side connector 65, and is available in a series of types with different detection methods.

[0030] The sensor-side circuit board 63 is a circuit board that supplies power to the gas detection unit 62 and outputs the response result (analog response or digital response) of the gas detection unit 62. The sensor-side computer 64 converts the analog response (measurement result) of the gas detection unit 62 into a digital signal and outputs it. The sensor-side computer 64 further normalizes this digital signal and outputs it. Furthermore, the sensor-side computer 64 outputs its own type information and various setting information stored in the sensor-side memory. The sensor-side computer 64 receives a command signal transmitted from the main body-side computer 34 or the base-side computer 74, and generates and outputs a response signal based on the command.

[0031] The sensor-side connector 65 is detachably connected to a sensor receiving connector of the sensor base 70, which will be described later. The gas sensor 60 is fixed to the sensor base 70 by this sensor-side connector 65. The gas sensor 60 receives power from the outside (sensor base 70) via the sensor-side connector 65, is controlled from the outside, and receives commands (signals) from the outside. The gas sensor 60 also outputs analog signals, digital signals, and the like to the outside (sensor base 70) via the sensor-side connector 65. Note that pins corresponding to the number of electrical paths protrude from the sensor-side connector 65. Electrical connection is achieved by inserting these pins into pin holes in the sensor receiving connector.

[0032] (sensor-based) 9(B) and (C), the sensor base 70 has a base housing 71, a base-side circuit board 73, a base-side computer 74 and a base-side memory (not shown) mounted on the base-side circuit board 73, a sensor receiving connector 75 mounted on the base-side circuit board 73, and a main body receiving connector 77 mounted on the base-side circuit board 73. The base-side circuit board 73 provides a path for transmitting power and a path for transmitting and receiving signals.

[0033] The base housing 71 is a rectangular parallelepiped case, and the base side circuit board 73 is housed therein. The gas sensor 60 and the chamber 52 are arranged on the back surface of the base housing 71 (this back surface corresponds to the inner surface in the posture set in the main body 10). As shown in FIG. 10, the base housing 71 has a circular sensor insertion opening 71A formed at a location corresponding to the sensor receiving connector 75 of the base side circuit board 73. The sensor insertion opening 71A exposes the entire sensor receiving connector 75 and a part of the base side board 73 to the outside. The gas sensor 60 is inserted through the sensor insertion opening 71A, whereby the sensor receiving connector 75 and the sensor side connector 65 are connected. The base housing 71 has a square main body connection opening 71Z formed at a location corresponding to the main body receiving connector 77 of the base side circuit board 73, and the main body receiving connector 77 is exposed. The main body receiving connector 77 is electrically connected to the main body side connector 26A.

[0034] A base side engaging portion 79 having a pair of receiving groove structures is formed in the base housing 71. The chamber side engaging portion 55 of the chamber 52 engages with this base side engaging portion 79. When the user forcibly pulls the chamber 52 and the sensor base 70 apart, the engagement between the chamber side engaging portion 55 and the base side engaging portion 79 is released, and they can be separated from each other.

[0035] A hinge 71G is formed between the base housing 71 and the chamber 52. The chamber 52 and the sensor base 70 swing relative to each other due to the swing shaft of this hinge 71G. Therefore, when the engagement between the chamber side engaging portion 55 and the base side engaging portion 79 is released, the base housing 71 and the chamber 52 can swing relative to each other via the hinge 71G, but the connection between them is maintained. This prevents the chamber 52 from being dropped and damaged or lost during the work of attaching or detaching the gas sensor 60 to the base housing 71.

[0036] The base side computer 74 transmits the standardized digital signal received from the gas sensor 60 to the main body side computer 34. Although details will be described in the second embodiment, in the case of a gas detection module to which a plurality of gas sensors 60 (gas detection units 62) are connected, the base side computer 74 multiplexes the digital signal, converts it into a sequential signal, and transmits it to the main body side computer 34. If the gas sensor 60 is a type that does not have a built-in sensor side computer 64, the base side computer 74 can digitize and standardize the analog signal of the gas detection unit 62 instead of the sensor side computer 64. The base side computer 74 can output its own type information and various setting information stored in the base side memory to the main body side computer 34. The base side computer 74 can receive a command signal transmitted from the main body side computer 34 or the sensor side computer 64, and output a response signal based on the command.

[0037] (Sensor side interface to the main unit) 9(C), the arrangement of the sensor-side interface for connecting gas detection module 50 to main body 10 is defined by three points: main body receiving connector 77, chamber side inlet channel 52IN, and chamber side outlet channel 52OUT. In other words, this sensor-side interface completely matches the arrangement of the main body side interface in FIG. 4 (main body side connector 26A, main body side inlet 22IN, and main body side outlet 24OUT).

[0038] <Connection between the main unit and the gas detection module> 11 shows the connection state between the main body 10 and the gas detection module 50 in the gas detector 1. The main body side interface (the arrangement of the main body side connector 26A, the main body side inlet 22IN, and the main body side outlet 24OUT) and the sensor side interface (the main body receiving connector 77, the chamber side inlet 52IN, and the chamber side outlet 52OUT) are completely aligned, so that the two are connected by simply pushing the gas detection module 50 toward the back in the depth direction relative to the main body 10 (see FIG. 11(B)). Conversely, the two are separated by simply pulling the gas detection module 50 toward the front in the depth direction relative to the main body 10 (see FIG. 11(A)).

[0039] <Circuit configuration> FIG. 12A shows the overall circuit configuration of the gas detector 1.

[0040] (Main unit circuit configuration) The main body side circuit board 26 has a main body side computer 34, a first determination power supply unit 202, a second determination power supply unit 204, a first base power supply unit 206, a second base power supply unit 208, a third determination response unit 220, a heater power supply unit (additional function supply unit) 210, an external communication connector 28C, and a main body side connector 26A.

[0041] The main body side circuit board 26 includes, as electrical paths connected to the gas detection module 50 via the main body side connector 26A, a first determination path 102, a second determination path 104, a third determination path 116, a first base power path 106, a second base power path 108, a heater power path 110, a first communication path 112, a second communication path 118, and a reset path 114. The first determination path 102 and the second communication path 118 are realized as a single path.

[0042] The first determination power supply unit 202 is, for example, a 3.3V power supply and a first body-side resistor connected in series thereto, and supplies a first determination power to the gas detection module 50 via the first determination path 102. The second determination power supply unit 204 is, for example, a 3.3V power supply and a second body-side resistor connected in series thereto, and supplies a second determination power to the gas detection module 50 via the second determination path 104. The first base power supply unit 206 is, for example, a 5.0V power supply, and supplies a first base power to the gas detection module 50 via the first base power path 106. The second base power supply unit 208 is, for example, a 24V power supply, and supplies the first base power to the gas detection module 50 via the second base power path 108. The heater power supply unit (additional function supply unit) 210 is, for example, a variable voltage power supply, and supplies heater power that is variable (controlled) within a range of 1.0V to 10.0V on the main body 10 side to the gas detection module 50 via the heater power path 110.

[0043] For example, the maximum supply voltage of the first determination power supply unit 202 and the second determination power supply unit 204 is set to be equal to or lower than, and preferably lower than, the minimum supply voltage of the first base power supply unit 206 and the second base power supply unit 208. This is to prevent breakdown of the gas detection module 50 due to the determination power supplied before the gas detection module 50 is determined exceeding the allowable voltage of the gas detection module 50.

[0044] Third determination response unit 220 is, for example, a third body-side resistor connected between third determination path 116 and ground, and manages the voltage level of third determination path 116. For example, the voltage level of third determination path 116 is a divided voltage of a third sensor-side resistor and a third body-side resistor of third determination power supply unit 706, which will be described later. In other words, by changing the voltage of third determination power supply unit 706 or the resistance value of the third sensor-side resistor, the voltage level of third determination path 116 can be changed.

[0045] The main body side computer 34 includes a first determination unit 34A that detects the voltage level of the first determination path 102, a second determination unit 34B that detects the voltage level of the second determination path 104, and a third determination unit 34C that detects the voltage level of the third determination path 116. Based on the voltage levels of the first to third determination units 34A to 34C, the type and the like of the gas detection module 50 are determined by the main body side computer 34.

[0046] The second communication path 118 transmits (outputs) a command signal generated by the main body computer 34 to the gas detection module 50. Therefore, the second communication path 118 is connected to the command transmission unit 34D of the main body computer 34. The second communication path 118 and the first determination path 102 merge in the main body circuit board 26 to form a single path, which is connected to the main body connector 26A. This reduces the number of pins (paths) of the main body connector 26A. In this embodiment, the number of pins of the main body connector 26A is set to 10 or less (specifically, 8), excluding the ground pin GND. When the second communication path 118 is to function, the general-purpose input setting of the first determination power by the first determination unit 34A may be switched to the communication output setting by the command transmission unit 34D in the main body computer 34.

[0047] The first communication path 112 receives (inputs) the digital signal transmitted from the gas detection module 50 at the main body side computer . Therefore, the first communication path 112 is connected to the signal receiving unit 34E of the main body side computer .

[0048] The reset path 114 transmits a reset signal generated by the main body computer 34 to the gas detection module 50. Therefore, the reset path 114 is connected to the reset transmission unit 34F of the main body computer 34. When the reset signal is released, gas detection is started in the gas detection module 50.

[0049] (Base circuit configuration) The base side circuit board 73 has a base side computer 74 , a sensor receiving connector 75 , a main body receiving connector 77 , a first determination response unit 702 , a second determination response unit 704 , and a third determination power supply unit 706 .

[0050] The base-side circuit board 73 includes a first determination path 102, a second determination path 104, a third determination path 116, a first base power path 106, a second base power path 108, a heater power path 110, a first communication path 112, a reset path 114, and a second communication path 118 as paths that electrically connect the main body receiving connector 77 and the sensor receiving connector 75. The first determination path 102 and the second communication path 118 share a single path. The first communication path 112, the reset path 114, and the second communication path 118 have the base-side computer 74 interposed therebetween.

[0051] The first determination response unit 702 is, for example, a first response-side resistor connected between the first determination path 102 and ground, and sets the voltage level of the first determination path 102. For example, when the supply voltage of the first determination power supply unit 202 is set to 3.3 V, the voltage level of the first determination path 102 is a divided voltage of the first body-side resistor and the first response-side resistor in the first determination power supply unit 202. In other words, when the value of the first body-side resistor is fixed, the voltage level of the first determination path 102 can be uniquely determined using the value of the first response-side resistor. This voltage level is detected by the first determination unit 34A of the main body computer 34. Therefore, if the value of the first response-side resistor of the first determination response unit 702 is set to be different from the value of the first response-side resistor of the first determination response unit in the gas detection module of the second and third embodiments described later, the voltage level detected by the main body computer 34 will also be different, and the type of the gas detection module 50 and / or the type of the sensor base 70 can be identified.

[0052] The second determination response unit 704 is, for example, a second response-side resistor connected between the second determination path 104 and ground, and sets the voltage level of the second determination path 104. For example, when the supply voltage of the second determination power supply unit 204 is set to 3.3 V, the voltage level of the second determination path 104 is a divided voltage of the second body-side resistor and the second response-side resistor in the second determination power supply unit 204. In other words, when the value of the second body-side resistor is fixed, the voltage level of the second determination path 104 can be uniquely determined using the value of the second response-side resistor. This voltage level is detected by the second determination unit 34B of the main body computer 34. Therefore, if the value of the second response-side resistor of the second determination response unit 704 is set to be different from the value of the second response-side resistor of the second determination response unit in the gas detection module of the second and third embodiments described later, the voltage level detected by the main body computer 34 will also be different, and the type of the gas detection module 50 and / or the type of the sensor base 70 can be identified.

[0053] Furthermore, in the main body computer 34, by combining the voltage level of the first decision path 102 and the voltage level of the second decision path 104, it becomes possible to discriminate between a wider variety of types of gas detection modules (details will be described later).

[0054] The third determination power supply unit 706 is, for example, a 3.3V power supply using a regulator (power supply IC) or the like, and a third sensor-side resistor connected in series thereto. For example, the voltage level of the third determination path 116 is a divided voltage of the third sensor-side resistor and the third body-side resistor of the third determination response unit 220 on the main body 10 side. The voltage level of the third determination path 116 is detected by a third determination unit 34C of the main body-side calculator 34. The voltage level of the third determination path 116 can be used to determine a special gas detection module that cannot be determined by combining the voltage levels of the first determination path 102 and the second determination path 104.

[0055] In this embodiment, the first determination response unit 702 and the second determination response unit 704 are provided on the base-side circuit board 73, but the present invention is not limited to this. For example, some or all of them may be provided on the sensor-side circuit board 63 (see FIG. 13A). In this way, even if the gas sensor 60 is replaced with a different type without replacing the sensor base 70, the main body-side calculator 34 can determine the type of the gas sensor 60 by making the values ​​of the first and third response-side resistors different for the different types of gas sensors 60.

[0056] The second communication path 118 extending from the main body receiving connector 77 is connected to the command receiving unit 74Din of the base side computer 74. The command received by this command receiving unit 74Din is output to the second communication path 118 connected to the command transmitting unit 74Dout of the base side computer 74, and is transmitted to the sensor receiving connector 75.

[0057] On the other hand, the first communication path 112 extending from the sensor receiving connector 75 is connected to the signal receiving unit 74Ein of the base side computer 74. After a predetermined process, the signal received by this command receiving unit 74Ein is output from the command transmitting unit 74Eout of the base side computer 74 to the first communication path 112 and transmitted to the main body receiving connector 77.

[0058] The reset path 114 extending from the main body receiving connector 77 is connected to the reset receiving unit 74Fin of the base side computer 74. The command received by this reset receiving unit 74Fin is output to the reset path 114 connected to the reset transmitting unit 74Fout of the base side computer 74, and is transmitted to the sensor receiving connector 75.

[0059] (Sensor side circuit configuration) The sensor-side circuit board 63 has a sensor-side computer 64 and a sensor-side connector 65. Furthermore, a gas detection unit 62 is connected to the sensor-side circuit board 63. Depending on the gas detection method, a heater unit 62H such as a precious metal coil may be built into the gas detection unit 62.

[0060] The sensor-side circuit board 63 includes a first determination path 102, a second determination path 104, a third determination path 116, a first base power path 106, a second base power path 108, a heater power path 110, a first communication path 112, a reset path 114, and a second communication path 118 as electrical paths connected to the sensor base 70 via the sensor-side connector 65. The first determination path 102 and the second communication path 118 share a single path.

[0061] The second communication path 118 extending from the sensor side connector 65 is connected to the command receiving unit 64Din of the sensor side computer 64. The sensor side computer 64 outputs a desired response based on the command received by the command receiving unit 64Din from the signal transmitting unit 64Eout. The signal transmitting unit 64Eout of the sensor side computer 64 is connected to the first communication path 112. This first communication path 112 extends to the sensor side connector 65.

[0062] The reset path 114 extending from the sensor-side connector 65 is connected to a reset receiving unit 64Fin of the sensor-side computer 64. By referring to the command received by this reset receiving unit 64Fin, the sensor-side computer 64 determines whether or not to output a signal from the signal transmitting unit 64Eout (whether or not to start communication).

[0063] The analog output of the gas detection unit 62 is transmitted to an analog receiving unit 64Kin of the sensor-side computer 64 via an analog output path 130. The sensor-side computer 64 converts the analog signal received by the analog receiving unit 64Kin into a digital signal, and after further normalizing it, outputs it from a signal transmitting unit 64Eout.

[0064] The first base power path 106 extending from the sensor side connector 65 is connected to the gas detection unit 62. As a result, the first base power is supplied to the gas detection unit 62. Furthermore, the second base power path 108 extending from the sensor side connector 65 is connected to the gas detection unit 62. As a result, the second base power is supplied to the gas detection unit 62. Furthermore, the heater power path 110 extending from the sensor side connector 65 is connected to the heater unit 62H. As a result, the heater power that has been controlled is supplied to the heater unit 62H. Note that the first base power and the second base power do not need to be supplied simultaneously, and appropriate power may be selectively supplied from the first base power and the second base power depending on the type of the gas sensor 60. In this case, in the base side circuit board 73 and / or the sensor side circuit board 63, either the first base power path 106 or the second base power path 108 can be omitted. Furthermore, if the gas detection unit 62 does not have a built-in heater unit 62H, it is not necessary to supply heater power. In this case, the heater power path 110 in the base side circuit board 73 and / or the sensor side circuit board 63 can be omitted.

[0065] <Gas detection program> Next, there will be described a gas detection program (gas detection procedure) executed in the gas detector 1. This gas detection program is executed by the main body side computer 34, the base side computer 74, and the sensor side computer 64.

[0066] FIG. 12B shows functions that the main body side computer 34, the base side computer 74, and the sensor side computer 64 realize by executing the gas detection program (gas detection procedure).

[0067] (Functions of the main computer) The main body side computer 34 has a discrimination input processing unit 3402, a sensor discrimination processing unit 3404, an auxiliary discrimination input processing unit 3406, an auxiliary sensor discrimination processing unit 3408, a base power supply processing unit 3410, a path function switching processing unit 3412, a control protocol switching processing unit 3414, a sensor setting information reading unit 3416, an output demultiplexer processing unit 3418, an input multiplexer processing unit 3420, and an additional function processing unit 3422.

[0068] After the main power of the main body 10 is turned ON, the judgment input processing unit 3402 controls the first judgment power supply unit 202 and the second judgment power supply unit 204 to supply the first judgment power and the second judgment power to the first judgment path 102 and the second judgment path 104.

[0069] The sensor determination processing unit 3404 determines the gas detection module connected to the main body 10 based on the voltage levels of the first determination path 102 and the second determination path 104 to which the first determination power and the second determination power are supplied. The voltage level of the third determination path 116 may be added to the determination conditions.

[0070] For example, the sensor determination processing unit 3404 makes a determination by referring to a sensor determination table shown in Fig. 14 stored in the main body memory. In this sensor determination table, the voltage level of the first determination path 102 is determined in multiple stages (here, three stages A1 to A3) and the voltage level of the second determination path 104 is determined in multiple stages (six stages B1 to B6). By combining these, the sensor determination processing unit 3404 can determine a total of 18 types of gas detection modules (sensor types). By combining the voltage level of the third determination path 116, even more types can be determined.

[0071] In this embodiment, the case where the discrimination input processing unit 3402 supplies power and makes a judgment based on the voltage level has been exemplified, but the present invention is not limited to this. The discrimination input processing unit 3402 may transmit a command to transmit type information, and the base side computer 74 and / or the sensor side computer 64 may return sensor type information (response value) stored in each memory, thereby allowing the sensor discrimination processing unit 3404 to discriminate the type of the gas detection module.

[0072] The auxiliary discrimination input processing unit 3406 supplies an auxiliary command or auxiliary power (hereinafter, auxiliary discrimination input) for auxiliary discrimination of detailed specifications of the gas detection module after the sensor discrimination processing unit 3404 has completed discrimination of the gas detection module (particularly the sensor base 70). In particular, the auxiliary discrimination input is supplied in order to discriminate the type of the gas sensor 60 mounted thereon, rather than the entire gas detection module 50. Note that in this embodiment, since it is assumed that the communication function is already ON before the auxiliary discrimination input processing unit 3406 is started, the auxiliary command is transmitted to the base side computer 74 and / or the sensor side computer 64 by using the second communication path 118. The auxiliary sensor discrimination processing unit 3408 discriminates the type of the gas sensor 60 by referring to the response value (auxiliary response value) transmitted from the base side computer 74 and / or the sensor side computer 64 (here, the sensor side computer 64 of the gas sensor 60).

[0073] For example, in the case of a gas detection module equipped with a plurality of gas sensors as described later in the second embodiment of Fig. 19, both the determination of the entire module (sensor base) and the individual determination of the plurality of gas sensors mounted thereon are required. In this case, since it is desirable to determine the entire gas detection module before the communication function is started in the first place, in this embodiment, the determination is made based on the voltage levels of the first determination path 102, the second determination path 104, etc., using the determination input processing unit 3402 and the sensor determination processing unit 3404. On the other hand, when the determination of the entire module (sensor base) is completed, a communication function (communication protocol) suitable for this gas detection module can be started between the main body side computer 34 and the base side computer 74, so that the auxiliary determination input processing unit 3406 and the auxiliary sensor determination processing unit 3408 perform detailed determination of the gas sensor by signal exchange using a command signal and an auxiliary response signal.

[0074] In this case, in the case of the gas detection module shown in Fig. 19, the gas sensor may not be installed or may fail, so communication between the base side computer and the sensor side computer is not guaranteed. Therefore, as shown in Fig. 19, the base side computer 2074 that receives an auxiliary command from the main body side computer 34 supplies power for determination to the first sensor side first determination response unit 2707A and the first sensor side second determination response unit 2708A of the first sensor side circuit board 2063A, detects the response voltage level on the base side computer 2074 side, determines each gas sensor, and transmits the determination result to the main body side computer 34 via the first communication path 112. This makes it possible to determine the gas sensor regardless of whether the sensor side computer is started or not.

[0075] The base power supply processing unit 3410 supplies base power to the gas detection module 50. In particular, based on the discrimination result of the gas detection module 50 by the sensor discrimination processing unit 3404, an appropriate base power is supplied to the gas detection module 50. At this time, the base power supply processing unit 3410 may control the voltage level of the base power, or may selectively supply an appropriate one from among a plurality of base power sources (a first base power source and a second base power source).

[0076] The path function switching processing unit 3412 switches between a mode (sensor determination mode) in which the first determination power is supplied to the first determination path 102 using the first determination power supply unit 202 to enable sensor determination by the first determination path 102, and a mode (signal transmission mode) in which a general-purpose output setting of the first determination power is changed to a communication setting to enable signal transmission by the second communication path 118. This allows a single path to be shared by both the first determination path 102 and the second communication path 118, making it possible to reduce the number of connector pins.

[0077] The control protocol switching processing unit 3414 switches the control protocol (control procedure) for controlling the gas detection module 50 based on the discrimination result of the gas detection module 50 by the discrimination input processing unit 3402 and the sensor discrimination processing unit 3404 and / or the discrimination result of the auxiliary sensor discrimination processing unit 3408. This makes it possible to realize sensor control suited to various gas detection methods that the gas detection unit 62 can employ.

[0078] The input multiplexer processing unit 3420 multiplexes a plurality of command signals generated by the main body side computer 34 to generate a sequential command. This sequential command is transmitted to the gas detection module 50 via the second communication path 118. Note that this multiplexing includes not only multiplexing a plurality of command signals for a single gas sensor 60, but also multiplexing commands for a plurality of gas sensors as in the gas detection module 50 of the second embodiment.

[0079] The output demultiplexer processing unit 3418 receives the multiplexed sequential output transmitted from the base side computer 74 and distributes it to individual outputs. The output demultiplexer processing unit 3418 is preferably used in the case of receiving a sequential output in which the measurement results (outputs) of a plurality of gas sensors are multiplexed, such as in the gas detection module 50 of the second embodiment.

[0080] The additional function processing unit 3422 determines the supply level (including whether or not to supply) of the additional function to the gas detection module 50 based on the determination result by the sensor determination processing unit 3404 and / or the determination result by the auxiliary sensor determination processing unit 3408. The supply level of the additional function may be controlled by referring to the sensor determination table shown in FIG. 14. Specifically, the additional function processing unit 3422 controls the heater power supply unit 210 to supply the desired controlled power to the gas detection module 50. When the gas detection module 50 or the gas sensor 60 is miniaturized, there are cases where a power source for the heater and its power control function cannot be incorporated inside. Therefore, in this embodiment, the heater power supply unit 210 is provided on the main body 10 side, which is outside the gas detection module 50, to supply the controlled power (additional power) to the gas detection module 50. When the gas detection module 50 or the gas sensor 60 is replaced due to a malfunction or the like, the heater power supply unit 210 remains on the main body 10 side, so that the number of parts to be replaced can be reduced, and maintenance costs can be reduced.

[0081] The sensor setting information reading unit 3416 receives required specification information transmitted from a required specification output processing unit 6406 of the sensor side computer 64, which will be described later. The body side computer 34 controls the voltage level of the base power and the voltage level of the heater power based on this required specification information.

[0082] (Base computer function) The base-side computer 74 has an input demultiplexer processing unit 7402 and an output multiplexer processing unit 7404. The input demultiplexer processing unit 7402 distributes multiplexed sequential commands transmitted from the input multiplexer processing unit 3420 of the main-body-side computer 34 into individual commands. When multiple gas sensors are mounted as in the gas detection module 50 of the second embodiment, the multiplexed commands are distributed and transmitted to each gas sensor. The output multiplexer processing unit 7404 multiplexes signals output from multiple gas sensors as in the gas detection module 50 of the second embodiment, outputs sequentially, and transmits them to the main-body-side computer 34.

[0083] (Function of the sensor side computer) The sensor side computer 64 has a standardization processing unit 6402, a type output processing unit 6404, and a required specification output processing unit 6406. The standardization processing unit 6402 digitizes the analog output acquired from the gas sensor 60, and standardizes this digital output in accordance with an output rule (output specification) set in advance in the main body side computer 34. Even if the gas sensor 60 is replaced with various types of gas sensors 60, the main body side computer 34 and the base side computer 74 can process the output data by this standardization processing unit 6402 without performing any special processing.

[0084] The type output processing unit 6404 outputs type information (e.g., information on the gas detection method) stored in a sensor-side memory (not shown) mounted on the sensor-side circuit board 63 to the main body-side computer 34 as a response based on an auxiliary command transmitted from the auxiliary determination input processing unit 3406 of the main body-side computer 34. This enables the auxiliary sensor determination processing unit 3408 of the main body-side computer 34 to determine the type of the gas sensor 60.

[0085] In response to a command transmitted from the sensor setting information reading unit 3416 of the main body computer 34, the required specification output processing unit 6406 outputs required specification information (e.g., information on the base voltage level, the necessity and the level of heater power, etc.) stored in a sensor side memory (not shown) mounted on the sensor side circuit board 63 to the main body side computer 34. This enables the sensor setting information reading unit 3416 of the main body side computer 34 to obtain the setting information of the gas sensor 60.

[0086] (Flow from turning on the main power to starting measurement) The procedure executed by the gas detector 1 will be described with reference to the flowchart of FIG. 15. First, when the main power supply of the gas detector 1 is turned ON in step S1002, the input for judgment is turned ON in step S1004. This "input for judgment ON" means that the first judgment power supply unit 202 and the second judgment power supply unit 204 start supplying the power for judgment. In step S1006, it is determined whether the gas detection module 50 has been identified. If the identification is not possible (NO), it means that the gas detection module 50 is not connected, the gas detection module 50 is broken, or a gas detection module that is not the object of the identification is connected. Therefore, the process returns to step S1004 and waits with the input for judgment ON. If the identification is possible in step S1006 (YES), the process proceeds to step S1008, and the base power suitable for the identified type is supplied to the gas detection module 50.

[0087] Next, the process proceeds to step S1010, where it is determined whether the determined type requires an additional function (e.g., a heater function). If the additional function is required (YES), the process proceeds to step S1012, where the additional function (e.g., heater power supply) is turned ON, and then the process proceeds to step S1014. On the other hand, if the additional function is not required (NO), the process skips step S1012 and proceeds to step S1014. In step S1014, the main body side computer 34 switches the first determination path 102 to the second communication path 118 by changing the setting from the general-purpose input state in which the power supply by the first determination power supply unit 202 in step S1004 is detected by the first determination unit 34A to a communication output state by the command transmission unit 34D. This completes preparations for communication.

[0088] Next, the process proceeds to step S1016, where the reset signal generated by the main body computer 34 is released, thereby turning on signal communication between the main body computer 34, the base computer 74, and the sensor computer 64. Thereafter, in step S1018, it is determined whether or not a further detailed determination (auxiliary determination) is necessary for the type of the gas detection module 50. For example, in the case of a model in which a plurality of gas sensors are mounted inside the gas detection module 50, it is determined that an auxiliary determination is necessary (YES), and the process proceeds to step S1020, where the auxiliary determination input is turned ON. Note that this "auxiliary determination input ON" means that an auxiliary command is sent from the auxiliary determination input processing unit 3406 of the main body computer 34. Thereafter, the process proceeds to step S1022, where the process waits for a response (a response of type information) from the sensor computer 64, and if appropriate type information has been acquired (YES), the process proceeds to step S1024. On the other hand, if an appropriate type response cannot be acquired in step S1022, the process returns to step S1020, and the auxiliary command is resent. If it is determined in step S1018 that further detailed determination (auxiliary determination) of the type of gas detection module 50 is not necessary (NO), then the above-mentioned steps S1020 and S1022 are skipped and the process proceeds to step S1024.

[0089] In step S1024, the main body side computer 34 acquires sensor setting information (required specification information) from the sensor side computer 64, and in step S1026, executes detailed adjustment of the base power, heater power, etc. based on this sensor setting information. Through the above procedures, the measurement preparation is completed, and in step S1028, gas measurement is started.

[0090] 12A and 12B, the base side computer 74, the first determination response unit 702, the second determination response unit 704, and the third determination power supply unit 706 are provided on the base side circuit board 73, but the present invention is not limited thereto. For example, as shown in FIG. 13A and FIG. 13B, the input demultiplexer processing unit 7402 and the output multiplexer processing unit 7404, which are functions of the base side computer 74, can be provided on the sensor side computer 64, so that the base side computer 74 can be omitted. Similarly, the first determination response unit 702, the second determination response unit 704, and the third determination power supply unit 706 can be mounted on the sensor side circuit board 63. In this way, the base side circuit board 73 can be used as a relay board between the main body side connector 26A and the sensor side connector 65. If the number of pins of the main body side connector 26A and the sensor side connector 65 differs, the difference in the number of pins can be absorbed by the base side circuit board 73.

[0091] Second Embodiment Next, a gas detector 2001 of the second embodiment will be described with reference to FIG. 16 onwards. The main body 10 of the gas detector 2001 is the same as that of the first embodiment, and therefore a description thereof will be omitted. As for a gas detection module 2050 which is detachably connected to the main body 10, a description will be focused on the differences from the gas detection module 50 of the first embodiment. For parts and members which are identical or similar between the gas detection module 2050 and the gas detection module 50, detailed descriptions thereof will be omitted by matching the last three digits of the reference numerals.

[0092] <Gas detection module> 16 and 17 show the overall configuration of the gas detection module 2050. The gas detection module 2050 has a chamber 2052, a first gas sensor 2060A, a second gas sensor 2060B, and a sensor base 2070.

[0093] (Chamber) The chamber 2052 has a chamber-side inlet passage 2052IN of a male structure (protruding structure) detachably connected to the main body-side inlet passage 22IN, a chamber-side outlet passage 2052OUT of a male structure (protruding structure) detachably connected to the main body-side outlet passage 24OUT, and a first internal space 2054A and a second internal space 2054B interposed between the chamber-side inlet passage 2052IN and the chamber-side outlet passage 2052OUT. The first internal space 2054A is a cylindrical space having a bottom surface, and its annular tip is the first sensor insertion port 2058A. The chamber-side inlet passage 2052IN and the chamber-side outlet passage 2052OUT are connected to the bottom surface of the first internal space 2054A. A rubber seal ring is installed in the first sensor insertion port 2058A. The first sensor insertion opening 2058A (seal ring) is brought into contact with a first seal surface 2068A, which is an annular tapered surface of the first gas sensor 2060A, so that the first internal space 2054A becomes a closed space.

[0094] The second internal space 2054B is arranged in parallel with the first internal space 2052A in the vertical direction. The second internal space 2054B is a cylindrical space having a bottom surface, and its annular end is the second sensor insertion port 2058B. The chamber side inlet path 2052IN and the chamber side outlet path 2052OUT are connected to the bottom surface of the second internal space 2054B. That is, the chamber side inlet path 2052IN and the chamber side outlet path 2052OUT are each branched and connected to both the first internal space 2052A and the second internal space 2054B. A rubber seal ring is installed in the second sensor insertion port 2058B. The second sensor insertion port 2058B (seal ring) is brought into contact with the second seal surface 2068B, which is the annular tapered surface of the second gas sensor 2060B, so that the second internal space 2054B becomes a closed space.

[0095] The chamber 2052 has a pair of chamber side engaging portions 2055 having an elastic claw structure. The chamber side engaging portions 2055 are engaged with base side engaging portions 79 having a pair of receiving groove structures on the sensor base 2070 side, whereby the chamber 2052 and the sensor base 2070 are coupled to each other.

[0096] (First Gas Sensor) As shown in Fig. 16(B), the first gas sensor 2060A includes a first sensor housing 2061A, a first gas detection unit 2062A, a first sensor side circuit board 2063A, a first sensor side computer 2064A and a first sensor side memory (not shown) mounted on the first sensor side circuit board 2063A, and a first sensor side connector 2065A mounted on the first sensor side circuit board 2063A. As shown in Fig. 17(A), a first seal surface 2068A is formed around the first sensor housing 2061A. When a first sensor insertion port 2058A (seal ring) of the chamber 2052 comes into contact with the first seal surface 2068A, the first internal space 2054A on the side of the first gas detection unit 2062A becomes a closed space.

[0097] The first sensor side computer 2064A converts the analog response of the first gas detection unit 2062A into a digital signal and outputs it. The first sensor side computer 2064A further normalizes the digital signal of the first gas detection unit 2062A and outputs it. Furthermore, the first sensor side computer 2064A outputs its own first type information and first setting information stored in the first sensor side memory. The first sensor side computer 2064A receives a command signal transmitted from the main body side computer 34 or the base side computer 2074 and outputs a response signal based on the command.

[0098] The first sensor side connector 2065A is detachably connected to a first sensor receiving connector 2075A of the sensor base 2070. The first gas sensor 2060A is fixed to the sensor base 2070 by the first sensor side connector 2065A.

[0099] (Second gas sensor) As shown in Fig. 16(B), the second gas sensor 2060B includes a second sensor housing 2061B, a second gas detection unit 2062B, a second sensor side circuit board 2063B, a second sensor side computer 2064B and a second sensor side memory (not shown) mounted on the second sensor side circuit board 2063B, and a second sensor side connector 2065B mounted on the second sensor side circuit board 2063B. As shown in Fig. 17(A), a second seal surface 2068B is formed around the second sensor housing 2061B. When a second sensor insertion port 2058B (seal ring) of the chamber 2052 comes into contact with the second seal surface 2068B, the second internal space 2054B on the second gas detection unit 2062B side becomes a closed space.

[0100] The second sensor side computer 2064B converts the analog response of the second gas detection unit 2062B into a digital signal and outputs it. The second sensor side computer 2064B further normalizes the digital signal of the second gas detection unit 2062B and outputs it. Furthermore, the second sensor side computer 2064B outputs its own second type information and second setting information stored in the second sensor side memory. The second sensor side computer 2064B receives a command signal transmitted from the main body side computer 34 or the base side computer 2074 and outputs a response signal based on the command.

[0101] The second sensor side connector 2065B is detachably connected to a second sensor receiving connector 2075B of the sensor base 2070. The second gas sensor 2060B is fixed to the sensor base 2070 by the second sensor side connector 2065B.

[0102] (sensor-based) As shown in FIG. 16(B), the sensor base 2070 has a base housing 2071, a base side circuit board 2073, a base side computer 2074 and a base side memory (not shown) mounted on the base side circuit board 2073, a first sensor receiving connector 2075A and a second sensor receiving connector 2075B mounted on the base side circuit board 2073, and a main body receiving connector 2077 mounted on the base side circuit board 2073.

[0103] 17, the base housing 2071 is a rectangular parallelepiped case, and houses a base side circuit board 2073 therein. In the base housing 2071, a circular first sensor insertion opening 2071A is formed at a location corresponding to the first sensor receiving connector 2075A, so that the entire first sensor receiving connector 2075A and a part of the base side board 2073 are exposed to the outside. In the base housing 2071, a circular second sensor insertion opening 2071B is formed at a location corresponding to the second sensor receiving connector 2075B, so that the entire second sensor receiving connector 2075B and a part of the base side board 2073 are exposed to the outside.

[0104] The first sensor receiving connector 2075A and the first sensor side connector 2065A are connected by inserting the first gas sensor 2060A through the first sensor insertion opening 2071A. Similarly, the second sensor receiving connector 2075B and the second sensor side connector 2065B are connected by inserting the second gas sensor 2060B through the second sensor insertion opening 2071B.

[0105] The base side computer 2074 multiplexes the standardized digital signals received from both the first gas sensor 2060A and the second gas sensor 2060B, and transmits them as a sequential signal to the main body side computer 34. If at least one of the first gas sensor 2060A and the second gas sensor 2060B does not have a sensor side computer, the base side computer 2074 may digitize or standardize the analog signal of the gas detection unit. Furthermore, the base side computer 2074 can output its own type information and various setting information stored in the base side memory to the main body side computer 34.

[0106] (Sensor side interface to the main unit) 16(C), the arrangement of the sensor-side interface for connecting the gas detection module 2050 to the main body 10 is defined by three locations: the main body receiving connector 2077, the chamber-side inlet channel 2052IN, and the chamber-side outlet channel 2052OUT. In other words, this sensor-side interface is completely consistent with the main body-side interface in FIG. 4 (the arrangement of the main body-side connector 26A, the main body-side inlet 22IN, and the main body-side outlet 24OUT) and the sensor-side interface of the gas detection module 50 of the first embodiment (FIG. 9(C)).

[0107] <Connection between the main unit and the gas detection module> 18 shows a connection state between the main body 10 and the gas detection module 2050 in the gas detector 2001. The main body side interface (the arrangement of the main body side connector 26A, the main body side inlet 22IN, and the main body side outlet 24OUT) and the sensor side interface (the main body receiving connector 2077, the chamber side inlet 2052IN, and the chamber side outlet 2052OUT) are completely aligned, so that the two are connected by simply pushing the gas detection module 2050 toward the rear in the depth direction relative to the main body 10 (see FIG. 18(B)). Conversely, the two are separated by simply pulling the gas detection module 2050 toward the front in the depth direction relative to the main body 10 (see FIG. 18(A)).

[0108] <Circuit configuration> FIG. 19 shows the overall circuit configuration of the gas detector 2001.

[0109] (Base circuit configuration) The base side circuit board 2073 has a base side computer 2074, a first sensor receiving connector 2075A, a second sensor receiving connector 2075B, a main body receiving connector 2077, a first determination response unit 2702, a second determination response unit 2704, and a third determination power supply unit 2706.

[0110] The base side circuit board 2073 has a first base power path 106, a second base power path 108, and a heater power path 110 as paths electrically connecting the main body receiving connector 2077 to the first sensor receiving connector 2075A and the second sensor receiving connector 2075B. The first base power path 106 extending from the main body receiving connector 2077 branches into a first base power path 106A for the first sensor and a first base power path 106B for the second sensor, which are respectively connected to the first sensor receiving connector 2075A and the second sensor receiving connector 2075B. The second base power path 108 extending from the main body receiving connector 2077 branches into a second base power path 108A for the first sensor and a second base power path 108B for the second sensor, which are respectively connected to the first sensor receiving connector 2075A and the second sensor receiving connector 2075B. The heater power path 110 extending from the main body receiving connector 2077 branches into a first sensor heater power path 110A and a second sensor heater power path 110B along the way, and are connected to a first sensor receiving connector 2075A and a second sensor receiving connector 2075B, respectively.

[0111] The base side circuit board 2073 further has a first determination path 102, a second determination path 104, and a third determination path 116 as electrical paths connected to the main body receiving connector 2077. A first determination response unit 2702 is connected to the first determination path 102, a second determination response unit 2704 is connected to the second determination path 104, and a third determination power supply unit 2706 is connected to the third determination path 116.

[0112] The base circuit board 2073 includes a first communication path 112 , a reset path 114 , and a second communication path 118 as signal transmission paths extending from the main body receiving connector 2077 to the base computer 2074 .

[0113] The base side circuit board 2073 includes a first communication path 112A on one side, a first reset path 114A, a second communication path 118A on one side, a first sensor side first determination path 120A, and a first sensor side second determination path 121A as communication paths extending from the base side computer 2074 to the first sensor receiving connector 2075A. The base side circuit board 2073 includes a first communication path 112B on the other side, a second reset path 114B, a second communication path 118B on the other side, a second sensor side first determination path 120B, and a second sensor side second determination path 121B as communication paths extending from the base side computer 2074 to the second sensor receiving connector 2075B.

[0114] As a result of the above, the second communication path 118 extending from the main body receiving connector 2077 branches into one side second communication path 118A and the other side second communication path 118B in the base side computer 2074, and extends to the first sensor receiving connector 2075A and the second sensor receiving connector 2075B. As a result, the multiplexed sequential instructions received by the base side computer 2074 from the main body side computer 34 are separated by the base side computer 2074, and distributed and transmitted to the one side second communication path 118A and the other side second communication path 118B.

[0115] On the other hand, the first communication path 112A on one side extending from the first sensor receiving connector 2075A and the first communication path 112B on the other side extending from the second sensor receiving connector 2075B merge with the first communication path 112 in the base side computer 2074 and extend to the main body receiving connector 2077. As a result, the standardized output signals (measurement results) received from the first gas sensor 2060A and the second gas sensor 2060B are multiplexed in the base side computer 2074 and transmitted to the first communication path 112.

[0116] In addition, the reset path 114 extending from the main body receiving connector 2077 branches into a first reset path 114A and a second reset path 114B in the base side computer 2074, and extends to a first sensor receiving connector 2075A and a second sensor receiving connector 2075B. As a result, the reset signal transmitted from the main body side computer 34 is distributed and transmitted to the first reset path 114A and the second reset path 114B.

[0117] (First sensor side circuit configuration) The first sensor side circuit board 2063A has a first sensor side computer 2064A, a first sensor side connector 2065A, a first sensor side first determination response unit 2707A, and a first sensor side second determination response unit 2708A. Furthermore, a first gas detection unit 2062A is connected to the first sensor side circuit board 2063A. Note that a first heater unit 2062A_H such as a precious metal coil may be built inside the first gas detection unit 2062A.

[0118] The first sensor side circuit board 2063A includes electrical paths connected to the sensor base 2070 via the first sensor side connector 2065A, such as a first base power path 106A for the first sensor, a second base power path 108A for the first sensor, a heater power path 110A for the first sensor, a first communication path 112A on one side, a first reset path 114A, a second communication path 118A on one side, a first sensor side first determination path 120A, and a first sensor side second determination path 121A.

[0119] The base side computer 2074 supplies first sensor side first determination power to the first sensor side first determination response unit 2707A of the first gas sensor 2060A via the first sensor side first determination path 120A. Furthermore, the base side computer 2074 supplies first sensor side second determination power to the first sensor side second determination response unit 2708A of the first gas sensor 2060A via the first sensor side second determination path 121A.

[0120] The base side calculator 2074 is equipped with a first sensor side first judgment unit (not shown) that detects the voltage level of the first sensor side first judgment path 120A, and a first sensor side second judgment unit (not shown) that detects the voltage level of the first sensor side second judgment path 121A.

[0121] The first sensor side first determination response unit 2707A is, for example, a first sensor first response side resistor connected between the first sensor side first determination path 120A and ground, and sets the voltage level of the first sensor side first determination path 120A. For example, when the voltage supplied from the base side computer 2074 is 3.3V, the voltage level of the first sensor side first determination path 120A is a divided voltage of the first base side resistor and the first sensor first response side resistor in the base side computer 2074. In other words, when the value of the first base side resistor is fixed, the voltage level of the first sensor side first determination path 120A can be uniquely determined using the value of the first sensor first response side resistor. This voltage level is detected by the first sensor side first determination unit of the base side computer 2074. Therefore, by appropriately setting the value of the first sensor first response side resistor of the first sensor side first determination response unit 2707A, it is possible to determine the presence or absence of connection of the first gas sensor 2060A and its type (including the type of a dummy gas sensor mounted for testing).

[0122] The determination result of the type, presence, etc. of the first gas sensor 2060A by the base-side computer 2074 is transmitted to the main body-side computer 34 via the first communication path 112 as a digital signal.

[0123] The first sensor side second response unit for determination 2708A is, for example, a first sensor second response side resistor connected between the first sensor side second determination path 121A and ground, and sets the voltage level of the first sensor side second determination path 121A. For example, when the voltage supplied from the base side computer 2074 is 3.3V, the voltage level of the first sensor side second determination path 121A is a divided voltage of the first base side resistor and the first sensor second response side resistor in the base side computer 2074. In other words, when the value of the first base side resistor is fixed, the voltage level of the first sensor side second determination path 121A can be uniquely determined using the value of the first sensor second response side resistor. This voltage level is detected by the first sensor side second determination unit of the base side computer 2074. Therefore, by appropriately setting the value of the first sensor second response side resistor of the first sensor side second response unit 2708A, it is possible to determine the presence or absence of connection of the first gas sensor 2060A and its type (including the type of a dummy gas sensor mounted for testing).

[0124] The determination result of the type, presence, etc. of the first gas sensor 2060A by the base-side computer 2074 is transmitted to the main body-side computer 34 via the first communication path 112 as a digital signal.

[0125] The analog output of the first gas detection unit 2062A is transmitted to the first sensor side computer 2064A via the first analog output path 2130A. The first sensor side computer 2064A converts the received analog signal into a digital signal, and after further normalizing it, outputs it from the first communication path 112A on one side.

[0126] The first sensor first base power path 106A and the first sensor second base power path 108A extending from the first sensor side connector 2065A are connected to the first gas detection unit 2062A. This allows the first base power and / or the second base power to be supplied to the first gas detection unit 2062A. Furthermore, the first sensor heater power path 110A extending from the first sensor side connector 2065A is connected to the first heater unit 2062A_H. This allows heater power to be supplied to the first heater unit 2062A_H.

[0127] (Second sensor side circuit configuration) The second sensor side circuit board 2063B has a second sensor side computer 2064B, a second sensor side connector 2065B, a second sensor side first determination response part 2707B, and a second sensor side second determination response part 2708B. Further, a second gas detection part 2062B is connected to the second sensor side circuit board 2063B. Note that a second heater part 2062B_H such as a precious metal coil may be built in the second gas detection part 2062B.

[0128] The second sensor side circuit board 2063B has electrical paths connected to the sensor base 2070 via the second sensor side connector 2065B, such as a first base power path 106B for the second sensor, a second base power path 108B for the second sensor, a heater power path 110B for the second sensor, a first communication path 112B on the other side, a second reset path 114B, a second communication path 118B on the other side, a first determination path 120B on the second sensor side, and a second determination path 121B on the second sensor side.

[0129] The base side computer 2074 supplies the second sensor side first determination power to the second sensor side first determination response unit 2707B of the second gas sensor 2060B via the second sensor side first determination path 120B. Furthermore, the base side computer 2074 supplies the second sensor side second determination power to the second sensor side second determination response unit 2708B of the second gas sensor 2060B via the second sensor side second determination path 121B.

[0130] The base side computer 2074 is equipped with a second sensor side first judgment unit (not shown) that detects the voltage level of the second sensor side first judgment path 120B, and a second sensor side second judgment unit (not shown) that detects the voltage level of the second sensor side second judgment path 121B.

[0131] The second sensor side first determination response unit 2707B is, for example, a second sensor first response side resistor connected between the second sensor side first determination path 120B and ground, and sets the voltage level of the second sensor side first determination path 120B. For example, when the voltage supplied from the base side computer 2074 is 3.3V, the voltage level of the second sensor side first determination path 120B is a divided voltage of the second base side resistor and the second sensor first response side resistor in the base side computer 2074. In other words, when the value of the second base side resistor is fixed, the voltage level of the second sensor side first determination path 120B can be uniquely determined using the value of the second sensor first response side resistor. This voltage level is detected by the second sensor side first determination unit of the base side computer 2074. Therefore, by appropriately setting the value of the second sensor first response side resistor of the second sensor side first determination response unit 2707B, it is possible to determine the presence or absence of connection of the second gas sensor 2060B and its type (including the type of a dummy gas sensor mounted for testing).

[0132] The determination result of the type, presence, etc. of the second gas sensor 2060B by the base-side computer 2074 is transmitted to the main body-side computer 34 via the first communication path 112 as a digital signal.

[0133] The second sensor side second determination response unit 2708B is, for example, a second sensor second response side resistor connected between the second sensor side second determination path 121B and ground, and sets the voltage level of the second sensor side second determination path 121B. For example, when the voltage supplied from the base side computer 2074 is 3.3V, the voltage level of the second sensor side second determination path 121B is a divided voltage of the second base side resistor and the second sensor second response side resistor in the base side computer 2074. In other words, when the value of the second base side resistor is fixed, the voltage level of the second sensor side second determination path 121B can be uniquely determined using the value of the second sensor second response side resistor. This voltage level is detected by the second sensor side second determination unit of the base side computer 2074. Therefore, by appropriately setting the value of the second sensor second response side resistor of the second sensor side second determination response unit 2708B, it is possible to determine the presence or absence of connection of the second gas sensor 2060B and its type (including the type of a dummy gas sensor mounted for testing).

[0134] The determination result of the type, presence, etc. of the second gas sensor 2060B by the base-side computer 2074 is transmitted to the main body-side computer 34 via the first communication path 112 as a digital signal.

[0135] In this embodiment, the base side computer 2074 preferably performs gas sensor determination by referring to a sensor determination table shown in Fig. 27 stored in its own memory. In this sensor determination table, the voltage level of the first sensor side first determination path 120A or the second sensor side first determination path 120B is determined in multiple stages (here, three stages A1 to A3), and the voltage level of the first sensor side second determination path 121A or the second sensor side second determination path 121B is determined in multiple stages (six stages B1 to B6). As a result, by combining these, the base side computer 2074 can determine a total of 18 types of gas sensors.

[0136] In this way, by doubling the type determination of the sensor base 2070 by the main body side computer 34 using the first determination response unit 2702, the second determination response unit 2704, etc. of the base side circuit board 2073, and the type determination of the first gas sensor 2060A and the second gas sensor 2060B by the base side computer 2074 using the first sensor side first determination response unit 2707A, the first sensor side second determination response unit 2708A, the second sensor side first determination response unit 2707B, the second sensor side second determination response unit 2708B, etc., it becomes possible to individually detect failure or malfunction of the first gas sensor 2060A and / or the second gas sensor 2060B. Moreover, the determination result by the base side computer 2074 is converted into a digital signal by the base side computer 2074 and transmitted via the first communication path 112, so that an increase in the number of pins of the main body receiving connector 2077 can be suppressed.

[0137] The analog output of the second gas detection unit 2062B is transmitted to the second sensor side computer 2064B via the second analog output path 2130B. The second sensor side computer 2064B converts the received analog signal into a digital signal, and after further normalizing it, outputs it from the other side of the first communication path 112B.

[0138] The second sensor first base power path 106B and the second sensor second base power path 108B extending from the second sensor side connector 2065B are connected to the second gas detection unit 2062B. This allows the first base power and / or the second base power to be supplied to the second gas detection unit 2062B. Furthermore, the second sensor heater power path 110B extending from the second sensor side connector 2065B is connected to the second heater unit 2062B_H. This allows heater power to be supplied to the second heater unit 2062B_H.

[0139] (Number of connector pins) In this embodiment, the number of pins (paths) of the first sensor side connector 2065A is 8, excluding the ground pin GND, and the number of pins of the second sensor side connector 2065B is 8, totaling 16. On the other hand, the number of pins (paths) of the body side connector 26A is 8, excluding the ground pin GND. That is, the total number of pins of the body side connector 26A connecting the sensor base 2070 and the body 10 is set to be smaller than the total number of pins of the first gas sensor 2060A and the second gas sensor 2060B. As a result, it is possible to make the body side connector 26A compact. The reduction in the number of pins of the body side connector 26A is realized by multiplexing / demultiplexing processing of commands and output signals, and function switching processing of a single path.

[0140] <Gas detection program> 20 shows functions realized by the main body side computer 34, the base side computer 2074, the first sensor side computer 2064A, and the second sensor side computer 2064B in the gas detector 2001 as a result of execution of a gas detection program (gas detection procedure). Note that the functional configurations of the main body side computer 34 and the base side computer 2074 are similar to those in the first embodiment, and therefore description thereof will be omitted.

[0141] (Function of the first sensor side computer) The first sensor side computer 2064A has a first standardization processing unit 6402A, a first type output processing unit 6404A, and a first required specification output processing unit 6406A. The first standardization processing unit 6402A digitizes an analog output acquired from the first gas sensor 2060A, and standardizes this digital output according to an output rule (output specification) set in advance in the main body side computer 34.

[0142] The first type output processing unit 6404A outputs, to the main body side computer 34, first type information (e.g., information regarding the gas detection method of the first gas sensor) stored in a sensor side memory (not shown) mounted on the first sensor side circuit board 2063A as a response based on an auxiliary command transmitted from the auxiliary determination input processing unit 3406 of the main body side computer 34.

[0143] In response to a command transmitted from the sensor setting information reading unit 3416 of the body-side computer 34, the first required specification output processing unit 6406A outputs the first required specification information (e.g., information on the base voltage level of the first gas sensor, the necessity and the level of heater power, etc.) stored in a sensor-side memory (not shown) mounted on the first sensor-side circuit board 2063A to the body-side computer 34. This enables the sensor setting information reading unit 3416 of the body-side computer 34 to acquire the setting information of the first gas sensor 2060A.

[0144] (Function of the second sensor side computer) The second sensor side computer 2064B has a second standardization processing unit 6402B, a second type output processing unit 6404B, and a second required specification output processing unit 6406B. The second standardization processing unit 6402B digitizes an analog output acquired from the second gas sensor 2060B, and standardizes this digital output according to an output rule (output specification) set in advance in the main body side computer 34.

[0145] The second type output processing unit 6404B outputs second type information (e.g., information regarding the gas detection method of the second gas sensor) stored in a sensor side memory (not shown) mounted on the second sensor side circuit board 2063B to the main body side computer 34 in response to an auxiliary command transmitted from the auxiliary determination input processing unit 3406 of the main body side computer 34.

[0146] In response to a command transmitted from the sensor setting information reading unit 3416 of the body-side computer 34, the second required specification output processing unit 6406B outputs the second required specification information (e.g., information on the base voltage level of the second gas sensor, whether heater power is required and its level, etc.) stored in a sensor-side memory (not shown) mounted on the second sensor-side circuit board 2063B to the body-side computer 34. This enables the sensor setting information reading unit 3416 of the body-side computer 34 to acquire the setting information of the second gas sensor 2060B.

[0147] (Base computer function) The input demultiplexer processing unit 7402 of the base side computer 2074 distributes the multiplexed sequential command transmitted from the input multiplexer processing unit 3420 of the main body side computer 34 to the first sensor side computer 2064A and the second sensor side computer 2064B. The output multiplexer processing unit 7404 of the base side computer 2074 multiplexes the standardized measurement result received from the first sensor side computer 2064A and the standardized measurement result received from the second sensor side computer 2064B to output sequentially, and transmits the sequentially output to the main body side computer 34. With this configuration, the main body side computer 34 can simultaneously control the multiple gas sensors 2060A and 2060B built into the gas detection module 2050.

[0148] (Flow from turning on the main power to starting measurement) The flow from turning on the main power supply to starting measurement in the second embodiment is the same as the procedure described with reference to the flowchart in FIG. 15 in the first embodiment, and therefore a description thereof will be omitted here.

[0149] <Third embodiment> A gas detector 3001 of the third embodiment will be described with reference to Fig. 21 and subsequent figures. The main body 10 of the gas detector 3001 is the same as that of the first embodiment, and therefore description thereof will be omitted. Here, with regard to a gas detection module 3050 that is detachably connected to the main body 10, the following description will focus on the differences from the gas detection module 50 of the first embodiment. For parts and members that are the same or similar between the gas detection module 3050 and the gas detection module 50, detailed description will be omitted by matching the last three digits of the reference numerals.

[0150] <Gas detection module> The gas detection module 3050 has a chamber 3052 shown in Fig. 21 and a sensor unit 3080 shown in Fig. 22. The chamber 3052 and the sensor unit 3080 are separable from each other.

[0151] (Chamber) As shown in FIG. 21, the chamber 3052 has a chamber-side inlet 3052IN having a male structure (protruding structure) detachably connected to the main body-side inlet 22IN, a chamber-side outlet 3052OUT having a male structure (protruding structure) detachably connected to the main body-side outlet 24OUT, and an internal space 3054 interposed between the chamber-side inlet 3052IN and the chamber-side outlet 3052OUT. The internal space 3054 is a cylindrical (disk-shaped) space having a bottom surface, and the annular edge of the cylinder is the unit insertion port 3058. A connecting protrusion 3061A (described later) of the sensor unit 3080 is inserted into this unit insertion port 3058. The chamber-side inlet 3052IN and the chamber-side outlet 3052OUT are connected to the bottom surface of the internal space 3054. A rubber seal ring is installed in the unit insertion port 3058. By bringing this unit insertion opening 3058 (seal ring) into contact with the periphery of a connecting protrusion 3061A (described later) of the sensor unit 3080, the internal space 3054 becomes a closed space.

[0152] The chamber 3052 has an elastic portion 3059 that protrudes in a U-shape toward the rear side in the depth direction in the installation posture on the main body 10. The elastic portion 3059 is elastically displaceable in the up and down direction. The elastic portion 3059 has a chamber side engagement portion 3055 having a claw structure.

[0153] The chamber side inlet passage 3052IN and the chamber side outlet passage 3052OUT are connected to the main body side inlet passage 22IN and the main body side outlet passage 24OUT, and at the same time, the chamber side engagement portion 3055 is engaged with the main body side engagement portion 49 (see Figure 24), which serves as a receiving groove structure on the main body 10 side, thereby fixing the chamber 3052 to the main body 10.

[0154] (sensor unit) As shown in FIG. 22, the sensor unit 3080 includes a unit housing 3081, a gas sensor 3060, a main body receiving connector 3077 provided in the unit housing 3081, a unit side circuit board 3073, a unit side computer 3074, and a unit side memory (not shown).

[0155] The unit housing 3081 is a rectangular parallelepiped case, and contains therein the gas sensor 3060, the unit side circuit board 3073, the unit side computer 3074, etc. The gas sensor 3060 is electrically connected directly to the unit side circuit board 3073 inside the unit housing 3081. As a result, the sensor unit 3080 is designed such that the gas sensor 3060 alone cannot be detachably replaced.

[0156] The gas sensor 3060 is further formed with a cylindrically protruding connecting protrusion 3061A. An end face of the connecting protrusion 3061A becomes a detection surface of the gas sensor 3060. A plurality of (four in this example) vent holes 3061B for taking in gas into the gas sensor 3060 are formed in this end face. Meanwhile, the unit housing 3081 is formed with an opening 3081A for exposing and protruding the connecting protrusion 3061A of the gas sensor 3060 to the outside. By inserting the connecting protrusion 3061A of the gas sensor 3060 protruding from the opening 3081A into the unit insertion port 3058 of the chamber 3052, the internal space 3054 of the chamber 3052 becomes a closed space.

[0157] In the present embodiment, the connecting protrusion 3061A, which is a part of the housing of the gas sensor 3060, and the unit housing 3081 are separate members, but the present invention is not limited to this. The unit housing 3081 itself may also serve as a part of the housing of the gas sensor 3060. From another perspective, this means that the connecting protrusion 3061A of the gas sensor 3060 also serves as a part of the unit housing 3081 when the sensor unit 3080 is viewed as a whole.

[0158] The unit side computer 3074 is mounted on the unit side circuit board 3073. The unit side computer 3074 converts an analog response output from the gas sensor 3060 into a digital signal and outputs it. The unit side computer 3074 further normalizes this digital signal. Furthermore, the unit side computer 3074 outputs its own type information and setting information stored in the unit side memory. The unit side computer 3074 receives a command signal transmitted from the main body side computer 34 and outputs a response signal based on the command.

[0159] Although not specifically shown here, if the unit housing 3081 has multiple gas sensors built in, the unit side computer 3074 may multiplex the standardized digital signals from each gas sensor and transmit them to the main body side computer 34 as a sequential signal.

[0160] In the unit housing 3081, a rectangular main body connection opening 3081Z is formed at a location corresponding to the main body receiving connector 3077 of the unit side circuit board 3073, and the main body receiving connector 3077 is exposed.

[0161] (Sensor side interface to the main unit)

[0162] 23 shows a gas detection module 3050 in which a sensor unit 3080 and a chamber 3052 are connected. The arrangement of the sensor-side interface for connecting the gas detection module 3050 to the main body 10 is defined by three points: the main body receiving connector 3077, the chamber-side inlet channel 3052IN, and the chamber-side outlet channel 3052OUT. In other words, this sensor-side interface completely matches the main body-side interface in FIG. 4 (the arrangement of the main body-side connector 26A, the main body-side inlet 22IN, and the main body-side outlet 24OUT), the sensor-side interface of the gas detection module 50 of the first embodiment, and the sensor-side interface of the gas detection module 2050 of the second embodiment.

[0163] <Connection between the main unit and the gas detection module> 24 shows the connection state of the main body 10 and the gas detection module 3050 in the gas detector 3001. The main body side interface (the arrangement of the main body side connector 26A, the main body side inlet 22IN, and the main body side outlet 24OUT) and the sensor side interface (the main body receiving connector 3077, the chamber side inlet 3052IN, and the chamber side outlet 3052OUT) are completely aligned. As shown in FIG. 24(B), first, the chamber 3052 is connected to the main body 10. At this time, the chamber 3052 is fixed to the main body 10 by engaging the chamber side engaging portion 3055 with the main body side engaging portion 49 on the main body 10 side.

[0164] Thereafter, as shown in FIG. 24(C), the sensor unit 3080 is attached to the main body 10 and the chamber 3052 which are integrated with each other by pushing the sensor unit 3080 in the depth direction. Conversely, the sensor unit 3080 is separated from the main body 10 and the chamber 3052 by simply pulling the sensor unit 3080 out toward the front in the depth direction (see FIG. 24(B)). In this way, when replacing with another sensor unit 3080 having a different gas detection method, it is possible to easily remove and attach only the sensor unit 3080 while leaving the chamber 3052 on the main body 10 side. Note that when replacing with the gas detection module 50 of the first embodiment or the gas detection module 2050 of the second embodiment, the chamber 3052 can be removed from the main body 10 by deforming the elastic portion 3059 to release the chamber side engaging portion 3055 and the main body side engaging portion 49.

[0165] <Circuit configuration> FIG. 25 shows the overall circuit configuration of the gas detector 3001.

[0166] (Unit side circuit configuration) The unit side circuit board 3073 has a unit side computer 3074 , a main body receiving connector 3077 , a first determination response unit 3702 , a second determination response unit 3704 , and a third determination power supply unit 3706 .

[0167] The unit side circuit board 3073 has a first base power path 106 and a second base power path 108 as paths that electrically connect the main body receiving connector 3077 and the gas sensor 3060. This allows the first base power and / or the second base power to be supplied to the gas sensor 3060. The unit side circuit board 3073 is provided with a heater power path 108X that uses the second base power path 108, and the heater power is controlled by a heater internal control unit 3090. This heater power is supplied to a heater unit 3062H such as a precious metal coil. Therefore, the power supply by the heater power supply unit 210 in the main body side circuit board 26 is stopped.

[0168] The unit side circuit board 3073 further has a first determination path 102, a second determination path 104, and a third determination path 116 as electrical paths connected to the main body receiving connector 3077. A first determination response unit 3702 is connected to the first determination path 102, a second determination response unit 3704 is connected to the second determination path 104, and a third determination power supply unit 3706 is connected to the third determination path 116.

[0169] The unit side circuit board 3073 includes a first communication path 112 , a reset path 114 , and a second communication path 118 as signal transmission paths extending from the main body receiving connector 3077 to the unit side computer 3074 .

[0170] The analog output from the gas sensor 3060 is transmitted to the unit side computer 3074 via the analog output path 3130. The unit side computer 3074 converts the received analog signal into a digital signal, and outputs the digital signal from the first communication path 112 after standardizing it.

[0171] <Gas detection program> 25 shows functions that are realized by the main body side computer 34 and the unit side computer 3074 in the gas detector 3001 as a result of the gas detection program (gas detection procedure) being executed. Note that the functional configuration of the main body side computer 34 is similar to that of the first embodiment and the like, and therefore description thereof will be omitted.

[0172] (Unit side computer function) The unit side computer 3074 has a standardization processing unit 7410, a type output processing unit 7406, and a required specification output processing unit 7408. The standardization processing unit 7410 digitizes the analog output acquired from the gas sensor 3060, and standardizes this digital output in accordance with an output rule (output specification) set in advance in the main body side computer 34.

[0173] The type output processing unit 7406 outputs type information (e.g., information regarding the gas detection method of the gas sensor) stored in a unit side memory (not shown) mounted on the unit side circuit board 3073 to the main body side computer 34 in response to an auxiliary command transmitted from the auxiliary determination input processing unit 3406 of the main body side computer 34.

[0174] In response to a command transmitted from the sensor setting information reading unit 3416 of the main body computer 34, the required specification output processing unit 7408 outputs required specification information (e.g., the base voltage level of the gas sensor, and information indicating that heater power is not required) stored in a sensor side memory (not shown) mounted on the unit side circuit board 3073 to the main body side computer 34. This enables the sensor setting information reading unit 3416 of the main body side computer 34 to acquire the setting information of the gas sensor 3060.

[0175] The unit side computer 3074 further has an input demultiplexer processing unit 7402 and an output multiplexer processing unit 7404. The input demultiplexer processing unit 7402 distributes multiplexed sequential commands transmitted from the input multiplexer processing unit 3420 of the main body side computer 34. This is preferably used when the sensor unit 3080 has multiple built-in gas sensors.

[0176] When the sensor unit 3080 has multiple gas sensors built in, the output multiplexer processing unit 7404 multiplexes the standardized measurement results received from the multiple gas sensors to output sequentially and transmits the multiple gas sensors to the main body computer 34. With this configuration, when the gas detection module 3050 has multiple gas sensors mounted thereon, the main body computer 34 can simultaneously control them.

[0177] As can be seen by comparing the unit side computer 3074 of the third embodiment with the base side computer 74 and the sensor side computer 64 of the first embodiment, the unit side computer 3074 integrally has the functions of both the base side computer 74 and the sensor side computer 64 of the first embodiment. In other words, the unit side computer 3074 is a concept that includes the base side computer 74 and the sensor side computer 64.

[0178] (Flow from turning on the main power to starting measurement) The flow from turning on the main power supply to starting measurement in the third embodiment is the same as the procedure described with reference to the flowchart of FIG. 15 in the first embodiment, and therefore a description thereof will be omitted here.

[0179] As described above, the gas detector 1, 2001 of the first and second embodiments comprises a common main body 10, a chamber 52, 2052 arranged in a state that allows it to be separated (detached) from the main body 10, a gas sensor 60, 2060A, 2060B arranged in a state that allows it to be separated (detached) from the chamber, and a sensor base 70, 2070 arranged in a state that allows it to be separated (detached) from the gas sensor and the main body.

[0180] In this way, it becomes possible to freely select and use the most suitable gas sensor from various types of gas sensors according to the purpose of use. Furthermore, if the gas sensor or the sensor base breaks down, it is only necessary to replace the gas sensor or the sensor base, which reduces the maintenance burden.

[0181] In the gas detector 1, 2001 of the first and second embodiments, the chamber 52, 2052 has a sensor insertion opening 58, 2058A, 2058B into which the gas sensor 60, 2060A, 2060B is inserted. The gas sensor 60, 2060A, 2060B has an annular sensor side seal surface 68, 2068A, 2068B that can abut against the sensor insertion opening. As a result, by simply swinging the chamber 52, 2052 and fixing it to the sensor base 70, 2070, the sensor insertion opening 58, 2058A, 2058B and the sensor side seal surface 68, 2068A, 2068B come into abutment, and the internal space 54, 2054A, 2054B can be made into a closed space.

[0182] At this time, since the chamber 52, 2052 has the chamber side engaging portion 55, 2055 and the sensor base 70, 2070 has the base side engaging portion 79, 2079 that engages with the chamber side engaging portion 55, 2055, the chamber 52, 2052 can be easily fixed to the sensor base 55, 2055. On the other hand, by releasing the mutual engagement state, the chamber 52, 2052 can be moved (relatively swung) relative to the sensor base 70, 2070, so that the gas sensor 60, 2060A, 2060B can be easily replaced.

[0183] In particular, in the case of the gas detection module 2050 exemplified in the gas detector 2001 of the second embodiment, since a plurality of gas sensors 2060A, 2060B can be attached to the sensor base 2070, a plurality of target gases can be simultaneously detected, or the same target gas can be detected by different methods. In the base side computer 2074, the input demultiplexer processing unit 7402 can distribute the multiplexed sequential command transmitted from the main body side computer 34 to the plurality of gas sensors 2060A, 2060B. At the same time, in the base side computer 2074, the output multiplexer processing unit 7404 can multiplex the standardized measurement results received from the plurality of gas sensors 2060A, 2060B, convert them into sequential output, and transmit them to the main body side computer 34. With these configurations, the main body side computer 34 can simultaneously control the plurality of gas sensors 2060A, 2060B built into the gas detection module 2050.

[0184] As shown in the gas detectors 1, 2001, and 3001 of the first to third embodiments, the sensor-side interfaces of the gas detection module 50 of the first embodiment, the gas detection module 2050 of the second embodiment, and the gas detection module 3050 of the third embodiment are completely consistent with one another. This allows the three types of gas detection modules 50, 2050, and 3050 to be freely replaced with respect to the common main body 10.

[0185] For example, there may be a gas detection method in which the gas sensors 60, 2060A, 2060B are miniaturized and handling of the gas sensor alone is acceptable, as in the gas detection module 50, 2050 of the first and second embodiments, and a gas detection method in which the gas sensor 3060 is integrally built into the sensor unit 3080 and direct handling of the gas sensor alone should not be permitted, as in the gas detection module 3050 of the third embodiment.

[0186] In this way, when the specifications on the gas sensor side are diversified, it is difficult to make the interface of the gas sensor 60 of the first embodiment, the interface of the two gas sensors 2060A and 2060B of the second embodiment, and the interface of the sensor unit 3080 of the third embodiment match each other. Therefore, in the first to third embodiments, the connection interfaces on the main body 10 side of all the chambers 52, 2052, and 3052 are made to completely match. In other words, by interposing the chambers 52, 2052, and 3052 between various gas sensors and the main body 10, they function as adapters that ensure connection compatibility. As a result, the main body 10 can be shared among the three types of gas detection modules 50, 2050, and 3050.

[0187] In the gas detector 1, 2001 of the first and second embodiments, the main body side computer 34, the base side computer 74, 2074, and the sensor side computer 64, 2064A, 2064B are connected in series with each other. By connecting the three computers in this way, the main body side computer 34 can multiplex and transmit commands, and the base side computer 74, 2074 can distribute the multiplexed commands to each gas sensor. Similarly, the base side computer 74, 2074 can multiplex and transmit the measurement results (outputs) of each gas sensor, and the main body side computer 34 separates the multiplexed outputs to display the measurement results of each gas sensor individually on the display device. In addition, the multiplexing of commands and signals makes it possible to reduce the number of pins of the main body side connector 26A.

[0188] Furthermore, in the sensor side computers 64, 2064A, 2064B, the measurement results (outputs) of the gas sensors can be standardized (common protocol), so that signal processing in the main body side computer 34 and the base side computers 74, 2074 can be simplified.

[0189] The gas detector 1, 2001 of the first and second embodiments includes a heater power supply unit 210 serving as an additional function supply unit on the main body 10 side. The supply voltage of the heater power supply unit 210 is controlled by the main body side computer 34. In other words, the main body side computer 34 functions as an additional function control unit that controls the additional function supply unit. As a result, it is not necessary to incorporate a heater power supply or voltage control function, which are likely to become large, inside the gas detection module 50, 2050, so that the gas detection module 50, 2050 and the gas sensor 60, 2060A, 2060B mounted thereon can be made smaller. As a result, it is possible to replace only the gas sensor 60, 2060A, 2060B in the gas detection module 50, 2050. Note that, although the first and second embodiments have been exemplified as an example in which additional power such as heater power is supplied as an additional function, the present invention is not limited to this. For example, a high-frequency signal, an optical signal, or the like may be supplied as an additional signal (additional function) according to the purpose of the gas sensor.

[0190] Incidentally, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0191] 1 Gas detector 10 Main unit 14IN suction port 14OUT Exhaust port 15 Lever 18 Pump 20 Flow Sensor 22 Main body inlet path 24 Outlet route on main body side 26 Main body circuit board 26A Main unit connector 27 Main unit auxiliary board 27A flexible wiring 34 Main unit side calculator 49 Body side engagement part 50 Gas Detection Module 52 Chamber 54 Interior Space 55 Chamber side engagement part 58 Sensor insertion port 60 Gas Sensor 61 Sensor housing 62 Gas detector 62H Heater section 63 Sensor side circuit board 64 Sensor side computer 65 Sensor side connector 68 Sealing Surface 70 Sensor Base 71 Base chassis 73 Base side circuit board 74 Base computer 75 Connector 77 Connector 79 Base side engagement part 102 First Decision Path 104 Second Decision Path 106 First base power path 108 Second base power path 108X Heater Power Path 110 Heater power path 112 First Communication Route 114 Reset Path 116 Third Decision Path 118 Second Communication Path 130 Analog output path 202 First judgment power supply section 204 Second judgment power supply section 206 First Base Power Supply Division 208 Second Base Power Supply Unit 210 Heater power supply 220 Third judgment response part 702 First judgment response part 704 Second Judgment Response Part 706 Third judgment power supply section 2001 Gas detector 2050 Gas Detection Module 2052 Chamber 2060A First Gas Sensor 2060B Secondary Gas Sensor 2063A First sensor side circuit board 2063B Second sensor side circuit board 2064A First sensor side computer 2064B Second sensor side computer 2065A First Sensor Side Connector 2065B Second sensor side connector 2070 Sensor Base 2071 Base chassis 2071A First sensor insertion opening 2071B Second sensor insertion opening 2073 Base side circuit board 2074 Base computer 2075A Connector 2075B Connector 2077 Connector 2702 First judgment response part 2704 Second judgment response part 2706 Third judgment power supply section 2707A First sensor side first judgment response unit 2707B Second sensor side first judgment response unit 2708A Response unit for second judgment on the first sensor side 2708B Second sensor side second judgment response unit 3001 Gas detector 3050 Gas Detection Module 3052 Chamber 3054 Interior Space 3055 Chamber side engagement part 3058 Unit insertion port 3060 Gas Sensor 3073 Unit side circuit board 3074 Unit side computer 3077 Connector 3080 Sensor Unit 3081 Unit Chassis 3090 Heater internal control unit 3130 Analog output path 3402 Input processing unit for discrimination 3404 Sensor discrimination processing unit 3406 Auxiliary discrimination input processing unit 3408 Auxiliary sensor discrimination processing unit 3410 Base power supply processing unit 3412 Route function switching processing unit 3414 Control protocol switching processing unit 3416 Sensor setting information reading unit 3418 Output demultiplexer processing section 3420 Input multiplexer processing section 3422 Additional Function Processing Unit 3702 First judgment response part 3704 Second judgment response part 3706 Third judgment power supply section 6402 Standardization Processing Unit 6404 Type output processing unit 6406 Requirement specification output processing unit 7402 Input demultiplexer processing section 7404 Output multiplexer processing section 7406 Type output processing unit 7408 Requirement specification output processing unit 7410 Standardization Processing Unit

Claims

1. A gas detector for detecting a gas, comprising: a main body having a main body side inlet passage through which the gas flows and a main body side outlet passage through which the gas flows; a first gas detection module that is detachably disposed relative to the body and detects the gas; a second gas detection module detachably disposed relative to the body and configured to detect the gas; The first gas sensing module includes: a first chamber disposed in a separable state with respect to the main body, the first chamber having a first chamber side inlet passage detachably connected to the main body side inlet passage, a first chamber side outlet passage detachably connected to the main body side outlet passage, and a first internal space interposed between the first chamber side inlet passage and the first chamber side outlet passage; a first gas sensor disposed in a state in which it can be separated from the first chamber, and a gas detection portion of the first gas sensor is brought into contact with the gas passing through the first internal space; a first sensor base that is disposed in a separable state with respect to the first gas sensor, and has a first sensor receiving connector that is detachably connected to a first sensor side connector of the first gas sensor, and a first body receiving connector that is detachably connected to a body side connector of the body, thereby electrically connecting the gas sensor and the body; and The second gas sensing module includes: a second chamber disposed in a separable state with respect to the main body, the second chamber having a second chamber side inlet passage detachably connected to the main body side inlet passage, a second chamber side outlet passage detachably connected to the main body side outlet passage, and a second internal space interposed between the second chamber side inlet passage and the second chamber side outlet passage; A second sensor unit disposed in a state in which it can be separated from the second chamber; and The second sensor unit of the second gas detection module further comprises: A second housing; a second gas sensor disposed inside the second housing and in contact with the gas passing through the second internal space; a second body receiving connector disposed in the second housing and detachably connected to a body side connector of the main body; A gas detector characterized in that the connection layout of the first chamber side inlet path, the first chamber side outlet path, and the first body receiving connector to the body in the first gas detection module is the same as the connection layout of the second chamber side inlet path, the second chamber side outlet path, and the second body receiving connector to the body in the second gas detection module.

2. a shape of a connection interface between the first chamber and the first gas sensor in the first gas detection module and a shape of a connection interface between the second chamber and the second sensor unit in the second gas detection module are different from each other; 2. The gas detector of claim 1.

3. The first chamber has a first chamber side engagement portion, the first sensor base has a first base side engagement portion that engages with the first chamber side engagement portion, the first chamber is fixed to the first sensor base by engaging the first chamber side engaging portion with the first base side engaging portion; The second chamber has a second chamber side engagement portion, the main body has a second main body side engaging portion that engages with the second chamber side engaging portion, The second chamber is fixed to the main body by engaging the second chamber side engaging portion with the second main body side engaging portion.

2. The gas detector of claim 1.

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