Measurement device

Abstract

To provide a measurement device capable of securely avoiding a failure of a power supply IC due to an abnormal voltage higher than a normal voltage even if the abnormal voltage is output from a battery.SOLUTION: A power circuit has: a battery; a power supply IC connected between the battery and the electric circuit; a control circuit which stops the operation of the power supply IC if an abnormal voltage higher than a normal voltage is output from the battery; and a step-down circuit which steps down the abnormal voltage output from the battery down to the rated voltage of the power supply IC or lower, and then inputs the resulting voltage to the power supply IC.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a measurement device, and more particularly to a measurement device for measuring the temperature and vibration of a steam trap. [Background technology]

[0002] In plants equipped with steam piping systems, condensate (drain) may occur within the piping system due to heat exchange, heat radiation, etc. If this condensate is allowed to remain within the piping system, it will cause a decrease in operating efficiency, so generally, steam traps are installed at appropriate locations in the piping system, and the condensate is discharged outside the piping system using these steam traps.

[0003] If the sealing performance of a steam trap is impaired due to aging or malfunction, the steam in the steam piping system will leak to the outside through the steam trap, resulting in unnecessary steam loss. For this reason, the condition of steam traps is inspected periodically, such as once a year.

[0004] The following Patent Document 1 discloses a measuring device and a diagnostic device for diagnosing the state of a steam trap. The measuring device is a portable measuring device, and the diagnostic device is a tablet terminal or a notebook computer, etc., and the measuring device and the diagnostic device are capable of wireless communication with each other. The measuring device includes a temperature sensor that measures the surface temperature of each steam trap, a vibration sensor that measures the vibration intensity of each steam trap, a memory unit that stores measurement data output from the temperature sensor and the vibration sensor, a communication unit that transmits the measurement data to the diagnostic device, and a display unit. The diagnostic device diagnoses the state (normal or abnormal) of each steam trap based on the measurement data received from the measuring device, and transmits diagnostic data indicating the results of the diagnosis to the measuring device. The measuring device displays the results of the diagnosis for each steam trap on the display unit based on the diagnostic data received from the diagnostic device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-84418 A Summary of the Invention [Problem to be solved by the invention]

[0006] The measuring device has a built-in circuit board on which an electric circuit is formed, and driving power is supplied to the electric circuit from a power supply circuit.

[0007] 4 is a diagram showing the configuration of a power supply circuit 100 provided in the measuring device. The power supply circuit 100 includes a battery 161, a fuse element 162, and a power supply IC 164. The power supply circuit 100 supplies driving power from the battery 161 to an electric circuit 103.

[0008] The power supply IC 164 has a protection circuit 171. The protection circuit 171 stops the operation of the power supply IC 164 when a current equal to or greater than a first current value, which is greater than the current value during normal operation, flows through the electric circuit 103. This protects the electric circuit 103 from an overcurrent equal to or greater than the first current value.

[0009] When a current of a second current value (e.g., several amperes) greater than the first current value flows, the fuse element 162 cuts off the connection between the battery 161 and the power supply IC 164. This protects the power supply IC 164 and the electric circuit 103 from an overcurrent of the second current value or more.

[0010] However, in the power supply circuit 100 according to the background art, if an abnormal voltage higher than the normal voltage is output from battery 161 when an abnormality occurs during normal operation or when a voltage doubling test according to explosion-proof safety standards is performed, the abnormal voltage exceeding the rated voltage of power supply IC 164 will be input to power supply IC 164, which may cause power supply IC 164 to fail.

[0011] The present invention has been made to solve such problems, and has an object to provide a measuring device that can reliably avoid failure of a power supply IC caused by abnormal voltage, even if an abnormal voltage higher than the normal voltage is output from a battery. [Means for solving the problem]

[0012] A measuring device according to one embodiment of the present invention is a measuring device that measures the temperature and vibration of a steam trap and includes a probe that is brought into contact with the steam trap, an electric circuit that outputs temperature data and vibration data of the steam trap by performing electrical processing, including conversion into electric signals, on the temperature and vibration of the steam trap transmitted from the probe, and a power supply circuit that supplies driving power to the electric circuit, wherein the power supply circuit includes a battery, a power supply IC connected between the battery and the electric circuit, a control circuit that stops operation of the power supply IC when an abnormal voltage higher than a normal voltage is output from the battery, and a step-down circuit that steps down the abnormal voltage output from the battery to below the rated voltage of the power supply IC and inputs it to the power supply IC.

[0013] According to this aspect, the control circuit stops the operation of the power supply IC when an abnormal voltage higher than a normal voltage is output from the battery. Also, the step-down circuit steps down the abnormal voltage output from the battery to a voltage equal to or lower than the rated voltage of the power supply IC and inputs the voltage to the power supply IC. Therefore, even if an abnormal voltage higher than a normal voltage is output from the battery, it is possible to reliably avoid failure of the power supply IC due to the abnormal voltage. Effect of the Invention

[0014] According to the present invention, even if an abnormal voltage higher than a normal voltage is output from a battery, it is possible to reliably avoid failure of a power supply IC caused by the abnormal voltage. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram showing a simplified configuration of a portable measuring device according to an embodiment of the present invention; [Diagram 2] 1 is a diagram showing a simplified configuration of a power supply circuit according to a prerequisite technique of the present invention; [Diagram 3] FIG. 2 is a diagram illustrating a configuration example of a step-down circuit. [Figure 4] FIG. 1 is a diagram showing a configuration of a power supply circuit included in a measuring device according to the background art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0017] 1 is a simplified diagram showing the configuration of a portable measurement device 1 according to an embodiment of the present invention. Measurement device 1 has a function for measuring the temperature and vibration of a steam trap, and a function for diagnosing the state of the steam trap based on the measurement results. However, the diagnostic function may be provided in an external device (such as a diagnostic device or server device) of measurement device 1. Furthermore, the measurement device is not limited to being portable, and may be a stationary measurement device.

[0018] In a plant or the like equipped with a steam piping system, a number of steam traps are installed at appropriate positions in the piping system in order to discharge condensate (drain) generated within the piping system to the outside of the piping system. The condition of the steam traps is inspected by periodic inspection, such as once a year. An operator performing a periodic inspection carries a portable measuring device 1 and moves around the plant, inspecting each steam trap in turn using the measuring device 1. Note that inspection of steam traps is not limited to periodic inspections, and may also be irregular inspections.

[0019] The measuring device 1 includes probes (temperature probe P1 and vibration probe P2), a power supply circuit 2, and an electric circuit 3. The electric circuit 3 is formed on a circuit board built into the measuring device 1, and includes a temperature sensor 11, an amplifier circuit 12, an AD conversion circuit 13, a vibration sensor 21, a filter circuit 22, an amplifier circuit 23, an AD conversion circuit 24, a control unit 31, an operation unit 41, a display unit 42, a storage unit 43, and a communication unit 44.

[0020] The temperature probe P1 and the vibration probe P2 have an external shape of, for example, a stainless steel cylindrical pipe. The temperature probe P1 is arranged in a concentric positional relationship in the space inside the vibrating probe P2, without contacting the inner peripheral surface of the vibrating probe P2. The temperature probe P1 and the vibration probe P2 are brought into contact with the steam trap to be measured, thereby transmitting the temperature and vibration of the steam trap to the temperature sensor 11 and the vibration sensor 21.

[0021] The temperature sensor 11 is configured to include, for example, a pair of thermocouple wires and a temperature measurement circuit, and converts the temperature transmitted from the temperature probe P1 into an electric signal and outputs it. The electric signal output from the temperature sensor 11 is input to the amplifier circuit 12. The amplifier circuit 12 amplifies the input electric signal and outputs it. The electric signal output from the amplifier circuit 12 is input to the AD conversion circuit 13. The AD conversion circuit 13 converts the input analog electric signal into digital data and outputs it. The digital data (temperature data) indicating the temperature measurement value output from the AD conversion circuit 13 is input to the control unit 31.

[0022] The vibration sensor 21 is configured to include, for example, a piezoelectric acceleration sensor, and converts the vibration transmitted from the vibration probe P2 into an electric signal and outputs it. The electric signal output from the vibration sensor 21 is input to a filter circuit 22. The filter circuit 22 passes and outputs electric signals of a predetermined frequency band from the input electric signals. The electric signal output from the filter circuit 22 is input to an amplifier circuit 23. The amplifier circuit 23 amplifies and outputs the input electric signal. The electric signal output from the amplifier circuit 23 is input to an AD conversion circuit 24. The AD conversion circuit 24 converts the input analog electric signal into digital data and outputs it. The digital data (vibration data) indicating the vibration measurement value output from the AD conversion circuit 24 is input to the control unit 31.

[0023] The operation unit 41 is composed of operation switches and the like for the operator to input various information. The display unit 42 is composed of a liquid crystal display, an organic EL display, or the like. However, the operation unit 41 and the display unit 42 may be integrated by using a touch panel display. The storage unit 43 is composed of a rewritable semiconductor memory such as a flash memory, or the like. The communication unit 44 is composed of a communication module compatible with any communication method such as Bluetooth (registered trademark).

[0024] The control unit 31 is configured with a CPU and the like. The control unit 31 has a diagnosis unit 51 as a function realized by the CPU executing a predetermined program. The diagnosis unit 51 diagnoses the state of the steam trap based on the measurement data (temperature data and vibration data) input from the AD conversion circuits 13 and 24, and outputs diagnosis data indicating the result of the diagnosis. For example, the diagnosis unit 51 compares the input temperature data with a predetermined temperature threshold value set in advance, and also compares the input vibration data with a predetermined vibration threshold value set in advance. The diagnosis unit 51 diagnoses whether the steam trap is normal or abnormal (steam leakage, drain discharge failure, or blockage) according to the combination of these two comparison results. The control unit 31 creates diagnosis result information (inspection date, diagnosis result, etc.) including the diagnosis data of the steam trap, and stores the diagnosis result information in the storage unit 43. The control unit 31 also inputs the diagnosis data to the display unit 42. As a result, the diagnosis result of the steam trap is displayed on the display unit 42. Furthermore, the control unit 31 inputs the diagnostic result information of the steam trap to the communication unit 44. The communication unit 44 transmits the input diagnostic result information to a data processing device external to the measurement device 1.

[0025] The power supply circuit 2 supplies the electric circuit 3 with power for driving each of a plurality of elements (devices, circuits, devices, etc.) included in the electric circuit 3.

[0026] 2 is a simplified diagram showing the configuration of a power supply circuit 2 according to an embodiment of the present invention. The power supply circuit 2 includes a battery 61, a fuse element 62, a step-down circuit 63, a control circuit 64, and a power supply IC 65. The power supply circuit 2 supplies driving power from the battery 61 to the electric circuit 3.

[0027] A fuse element 62 is connected downstream of the battery 61, a step-down circuit 63 is connected downstream of the fuse element 62, a power supply IC 65 is connected downstream of the step-down circuit 63, and an electric circuit 3, which is a load circuit, is connected downstream of the power supply IC 65.

[0028] The battery 61 is, for example, an alkaline battery, and outputs a voltage V1. The voltage V1 is, for example, 6.0 V during normal operation when no abnormality occurs.

[0029] The step-down circuit 63 steps down the input voltage V1 to a voltage V2 and outputs the voltage V2. The voltage V2 is input to the power supply IC 65.

[0030] FIG. 3 is a diagram showing a configuration example of the step-down circuit 63. The step-down circuit 63 is configured to include a series regulator having a transistor 80 and a resistor element 81. In the example of FIG. 3, the transistor 80 is an npn-type bipolar transistor. The collector C of the transistor 80 is connected to the fuse element 62, the emitter E is connected to the power supply IC 65, and the base B is connected to the ground line. The input voltage of the step-down circuit 63 is the voltage V1 of the collector C, and the output voltage is the voltage V2 of the emitter E. The voltage V2 is lower than the voltage V1 by the collector-emitter saturation voltage Vs. The amount of voltage drop of the voltage V2 relative to the voltage V1 can be set by the number of stages of the transistors 80 to be connected.

[0031] The voltage drop amount of the step-down circuit 63 is set so that the voltage V2 is equal to or lower than the rated voltage Vm of the power supply IC 65 in an abnormal state. When an abnormal voltage exceeding the normal voltage is output from the battery 61 and input to the step-down circuit 63, the step-down circuit 63 steps down the abnormal voltage V1 to a voltage V2 equal to or lower than the rated voltage Vm and inputs the voltage V2 to the power supply IC 65. For example, when the rated voltage Vm of the power supply IC 65 is 12.0 V and the maximum abnormal voltage is 12.4 V, the voltage drop amount required by the step-down circuit 63 is 0.4 V. When the collector-emitter saturation voltage Vs of the transistor 80 is 0.4 V, a voltage drop amount of 0.4 V can be realized by one stage of the transistor 80. Even during normal operation, a voltage drop occurs due to the step-down circuit 63, but since the collector-emitter saturation voltage Vs of the transistor 80 is sufficiently small compared to the normal voltage output from the battery 61, the effect of deterioration of the power supply efficiency is small.

[0032] The step-down circuit 63 may be configured to include a variable resistance element or the like instead of the series regulator.

[0033] The power supply IC 65 is configured to include, for example, a switching regulator. The power supply IC 65 steps down or steps up the voltage V2 input from the step-down circuit 63 to a voltage V4 according to the electric circuit 3 and outputs the voltage V4. The voltage V4 is input to the electric circuit 3, and thereby the driving power of the electric circuit 3 is supplied.

[0034] The power supply IC 65 has a protection circuit 71. The protection circuit 71 stops the operation of the power supply IC 65 when a current equal to or greater than a first current value I1, which is greater than the current value I0 during normal operation, flows through the electric circuit 3. This protects the electric circuit 3 from an overcurrent equal to or greater than the first current value I1.

[0035] The fuse element 62 cuts off the connection between the battery 61 and the step-down circuit 63 when a current equal to or greater than a second current value I2 (e.g., several amperes) greater than the first current value I1 flows, thereby protecting the power supply IC 65 and the electric circuit 3 from an overcurrent equal to or greater than the second current value I2.

[0036] The control circuit 64 stops the operation of the power supply IC 65 when an abnormal voltage exceeding the normal voltage is output from the battery 61. The control circuit 64 has a comparator (not shown) that compares a voltage V1, which is the output voltage of the battery 61, with a predetermined threshold voltage Vth. When the normal voltage of the battery 61 is 6.0V, the threshold voltage Vth is set to, for example, 6.4V.

[0037] When the voltage V1 is less than the threshold voltage Vth (i.e., normal operation), the control circuit 64 outputs a high-level signal V3. When the voltage V1 is equal to or greater than the threshold voltage Vth (i.e., abnormal operation), the control circuit 64 outputs a low-level signal V3.

[0038] The signal V3 is input to an active-high enable terminal 72 of the power supply IC 65. The power supply IC 65 executes operation when a high-level signal V3 is input to the enable terminal 72, and stops operation when a low-level signal V3 is input to the enable terminal 72. When the power supply IC 65 stops operation, the supply of drive power from the power supply IC 65 to the electric circuit 3 is stopped, and the measuring device 1 stops operating.

[0039] According to the measuring device 1 of this embodiment, when an abnormal voltage equal to or higher than the threshold voltage Vth, which is higher than the normal voltage, is output from the battery 61 when an abnormality occurs during normal operation or when a voltage doubling test according to the explosion-proof safety standard is performed, the control circuit 64 inputs a low-level signal V3 to the enable terminal 72 to stop the operation of the power supply IC 65. This makes it possible to avoid a failure of the power supply IC 65 due to the abnormal voltage, and to prevent smoke or fire from the electric circuit 3 caused by the operation being continued when the power supply circuit 2 is abnormal. In addition, the step-down circuit 63 steps down the abnormal voltage output from the battery 61 to a rated voltage Vm or lower of the power supply IC 65 and inputs it to the power supply IC 65. This makes it possible to avoid a voltage V2 exceeding the rated voltage Vm being input to the power supply IC 65 even if the operation of the power supply IC 65 is not stopped due to a malfunction of the control circuit 64 when the power supply circuit 2 is abnormal. As a result, even if an abnormal voltage higher than the normal voltage is output from the battery 61, it is possible to reliably avoid a failure of the power supply IC 65 caused by the abnormal voltage. [Explanation of symbols]

[0040] 1. Measurement equipment 2 Power circuit 3 Electrical Circuits 61 Batteries 63 Step-down circuit 64 Control circuit 65 Power IC P1 Temperature Probe P2 Vibration Probe

Claims

[Claim 1] A measuring device for measuring temperature and vibration of a steam trap, comprising: A probe that is in contact with the steam trap; an electric circuit that performs electrical processing, including conversion into an electric signal, on the temperature and vibration of the steam trap transmitted from the probe, to output temperature data and vibration data of the steam trap; a power supply circuit for supplying driving power to the electric circuit; Equipped with The power supply circuit includes: Batteries and a power supply IC connected between the battery and the electric circuit; a control circuit that stops operation of the power supply IC when an abnormal voltage higher than a normal voltage is output from the battery; a step-down circuit that steps down the abnormal voltage output from the battery to a rated voltage of the power supply IC or lower and inputs the voltage to the power supply IC; A measuring device having the above structure.

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