A hand-held relative humidity calibrator based on saturated salt solution

Abstract

The present invention provides a handheld relative humidity calibrator based on a saturated salt solution, comprising: a salt tank, a body, a measurement and control circuit, a lithium battery pack, a test chamber assembly, a base, and a sensor sealing and locking device. The salt tank is a hollow columnar body with a sealed bottom and an external thread provided on the outer side of the top; a hollow and mutually independent first chamber and a second chamber are provided inside the body. A stepped groove is provided on the inner side wall of the top of the first chamber, and the bottom of the second chamber is sealed; the lithium battery pack is connected to the measurement and control circuit; the test chamber assembly is a hollow columnar body with a sealed bottom, and a through groove for gas diffusion is provided on the outer side of the middle part, and a liquid separation and breathable membrane is attached to the outer side of the middle part. A boss with a middle protrusion is provided at the top, and an external thread is provided on the outer side above the boss; the test chamber assembly is placed into the first chamber; the base is fixedly connected to the body; the sensor sealing and locking device seals and locks the relative humidity sensor. The calibration cost of the relative humidity can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor calibration, and more particularly, to a handheld relative humidity calibrator based on a saturated salt solution. Background Art

[0002] In the calibration of relative humidity sensors and relative humidity testing instruments, there are, including but not limited to, constant temperature and humidity chambers, desktop temperature and humidity calibration instruments, and calibration devices based on the saturated salt principle. Among them, the calibration based on the saturated salt principle is a relatively widely used relative humidity calibration. Since a saturated salt solution can form a certain amount of relative humidity in a sealed space, at a constant temperature, a saturated salt solution can provide a constant relative humidity. However, since the relative humidity calibration device based on a saturated salt solution is related to environmental temperature, air pressure, etc., especially the influence of temperature is more obvious. Therefore, before testing, it is necessary to correct according to the current temperature. Currently, the relative humidity calibration device based on a saturated salt solution is large in volume and high in cost, and cannot meet the needs of outdoor mobile relative humidity calibration. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a handheld relative humidity calibrator based on a saturated salt solution to reduce the calibration cost of relative humidity.

[0004] In a first aspect, an embodiment of the present invention provides a handheld relative humidity calibrator based on a saturated salt solution, including: a salt tank, a body, a measurement and control circuit, a lithium battery pack, a test chamber assembly, a base, and a sensor sealing and locking device. The salt tank is a hollow columnar body, sealed at the bottom, and provided with an external thread on the outer side of the top;

[0005] The body is provided with a hollow and independent first chamber and second chamber. At a predetermined distance upward from the bottom end of the first chamber, a through hole is provided. On the inner side wall of the through hole, an internal thread matching the external thread provided on the top of the salt tank is provided. On the inner side wall of the top, a stepped groove is provided, and a positioning screw hole is provided at the top end. The bottom of the second chamber is sealed;

[0006] The measurement and control circuit includes a temperature and humidity detection circuit and a display circuit;

[0007] The lithium battery pack is connected to the measurement and control circuit to provide power for the measurement and control circuit. The measurement and control circuit and the lithium battery pack are placed and fixed in the second chamber through the top of the second chamber;

[0008] The test chamber assembly is a hollow columnar body with a sealed bottom. There are through grooves for gas diffusion on the outer side of the middle part. The liquid separation and breathable membrane is attached to the outer side of the middle part. The top is provided with a boss with a middle protrusion. The outer side above the boss is provided with an external thread. The test chamber assembly is placed into the first chamber. The boss overlaps on the stepped groove and seals the stepped groove. The space of the first chamber under the stepped groove and the space of the salt tank form a saturated salt solution storage chamber.

[0009] The base has a screw hole at the top corresponding to the position of the screw hole opened at the top of the body. This screw hole and the screw hole opened at the top of the body are fixed to connect the base and the body through screws. Corresponding to the position where the first chamber is opened on the body, there is a through hole matching the size above the boss of the test chamber assembly.

[0010] The sensor sealing and locking device is used to seal and lock the relative humidity sensor placed in the hollow columnar body of the test chamber assembly in combination with the external thread opened on the outer side above the boss. The sensor sealing and locking device and the space in the hollow columnar body of the test chamber assembly form a sealed test chamber.

[0011] The display circuit is arranged on the outer side of the body. The temperature and humidity detection circuit is used to detect the temperature and humidity in the test chamber where the relative humidity sensor is placed and display the detected temperature and humidity through the display circuit.

[0012] Combined with the first aspect, the embodiment of the present invention provides the first possible implementation manner of the first aspect. Among them, the sensor sealing and locking device includes: a boss fixed cover, an adjustable locking unit, and an end cover. Among them,

[0013] The boss fixed cover includes a first boss and a second boss. The size of the first boss is larger than that of the second boss. Among them, on the inner side of the first boss, there is an internal thread matching the external thread opened on the outer side above the boss. On the inner side of the second boss, there is an internal thread. On the outer side of the second boss, there is an external thread.

[0014] The adjustable locking unit is a hollow column with a wider upper part and a narrower lower part. The upper part is provided with evenly distributed and spaced opening grooves. The outer side of the lower part is provided with an external thread matching the internal thread opened on the inner side of the second boss.

[0015] The end cover is a hollow column. The inner side is provided with an internal thread matching the external thread opened on the outer side of the second boss.

[0016] Combined with the first possible implementation manner of the first aspect, the embodiment of the present invention provides a second possible implementation manner of the first aspect. After the relative humidity sensor is placed in the test chamber through the end cap, the adjustable locking unit, and the boss fixing cover, the external thread provided at the lower part of the adjustable locking unit is screwed into the internal thread provided on the inner side surface of the second boss, so that the spaced open slots at the upper part of the adjustable locking unit are gradually tightened until the adjustable locking unit is in close contact with the relative humidity sensor.

[0017] Combined with the first possible implementation manner of the first aspect, the embodiment of the present invention provides a third possible implementation manner of the first aspect, wherein the upper part size of the adjustable locking unit is smaller than the size of the second boss.

[0018] Combined with the first aspect and the first possible implementation manner of the first aspect, the embodiment of the present invention provides a fourth possible implementation manner of the first aspect, which further includes:

[0019] A sealing cover, with an internal thread provided on the inner side that matches the external thread provided on the outer side surface above the boss. After the relative humidity sensor is removed from the test chamber and the sensor sealing and locking device is removed, the opening of the test chamber assembly is screwed and sealed.

[0020] Combined with the first aspect and any one of the first to third possible implementation manners of the first aspect, the embodiment of the present invention provides a fifth possible implementation manner of the first aspect, wherein the test chamber assembly includes: a cylindrical hollow stainless steel column bracket and a liquid-separating and breathable membrane attached to the outer side surface of the stainless steel column bracket, wherein,

[0021] The outer side surface of the stainless steel column bracket is provided with evenly distributed through slots for air permeability, the bottom is sealed, the top is provided with a boss protruding in the middle, the stainless steel column bracket is inserted into the salt tank, a reserved space is formed with the bottom of the salt tank, the lower part of the boss forms a seal with the salt tank, and the outer side surface of the upper part of the boss is provided with an external thread.

[0022] Combined with the fifth possible implementation manner of the first aspect, the embodiment of the present invention provides a sixth possible implementation manner of the first aspect, wherein the stainless steel column bracket includes: a bracket base, a stainless steel body, and a bracket top cover. The bracket base is fixed to the bottom of the stainless steel body to seal the stainless steel body;

[0023] A first hollow space is formed inside the stainless steel body, and evenly distributed through slots are provided on the outer side surface. The liquid-separating and breathable membrane is attached to the outer side surface of the stainless steel column;

[0024] A second hollow space with the same inner diameter as the first hollow space is formed inside the bracket top cover. The bottom is sealed and connected to the salt tank, and the top is sealed and connected to the stepped groove.

[0025] Combined with any one of the first to third possible implementation manners of the first aspect, the embodiments of the present invention provide a seventh possible implementation manner of the first aspect, wherein the first chamber includes: a saturated salt solution storage chamber and a test chamber, and the saturated salt solution storage chamber and the test chamber are arranged coaxially and in opposite directions.

[0026] Combined with any one of the first to third possible implementation manners of the first aspect, the embodiments of the present invention provide an eighth possible implementation manner of the first aspect, further including: a fan, arranged in the test chamber assembly, which is a micro axial flow forced agitation fan, and is used to forcibly agitate and diffuse the gas that evaporates from the saturated salt solution storage area of the salt tank and diffuses into the test chamber through the liquid separation and air permeable membrane.

[0027] Combined with any one of the first to third possible implementation manners of the first aspect, the embodiments of the present invention provide a ninth possible implementation manner of the first aspect, wherein the measurement and control circuit monitors the temperature and humidity in the test chamber in real time, queries the pre-set mapping relationship table of temperature and humidity and salt tank types based on the monitored temperature and humidity, identifies the type of salt tank inserted in the saturated salt solution storage area, and queries the pre-set look-up table of temperature, salt tank type and standard relative humidity based on the monitored current temperature and the identified salt tank type to obtain the standard relative humidity corresponding to the current temperature and salt tank type, and calibrates the relative humidity sensor based on the queried standard relative humidity and the relative humidity value calibrated by the relative humidity sensor at this temperature.

[0028] The hand-held relative humidity calibrator based on a saturated salt solution provided by an embodiment of the present invention includes: a salt tank, a body, a measurement and control circuit, a lithium battery pack, a test chamber assembly, a base, and a sensor sealing and locking device. The salt tank is a hollow columnar body with a sealed bottom and an external thread provided on the outer side of the top; a hollow and independent first chamber and a second chamber are provided inside the body. A through hole is provided at a predetermined distance upward from the bottom end of the first chamber. An internal thread matching the external thread provided on the top of the salt tank is provided on the inner side wall of the through hole. A stepped groove is provided on the inner side wall of the top, and a screw hole for positioning is provided at the top end. The bottom of the second chamber is sealed; the measurement and control circuit includes a temperature and humidity detection circuit and a display circuit; the lithium battery pack is connected to the measurement and control circuit to provide power for the measurement and control circuit. The measurement and control circuit and the lithium battery pack are placed and fixed in the second chamber through the top of the second chamber; the test chamber assembly is a hollow columnar body with a sealed bottom. A through groove for gas diffusion is provided on the outer side surface of the middle part. A liquid separation and breathable membrane is attached to the outer side surface of the middle part. A convex platform with a middle protrusion is provided at the top. An external thread is provided on the outer side surface above the convex platform; the test chamber assembly is placed in the first chamber. The convex platform overlaps on the stepped groove and seals the stepped groove. The space of the first chamber below the stepped groove and the space of the salt tank form a saturated salt solution storage chamber; the base has a screw hole at the top end corresponding to the position of the screw hole provided at the top end of the body. The screw hole of the base and the screw hole provided at the top end of the body are fixedly connected to the base and the body through screws. A through hole matching the size above the convex platform of the test chamber assembly is provided at the position corresponding to the first chamber provided in the body; the sensor sealing and locking device is used to seal and lock the relative humidity sensor placed in the hollow columnar body of the test chamber assembly in combination with the external thread provided on the outer side surface above the convex platform. The sensor sealing and locking device and the space in the hollow columnar body of the test chamber assembly form a sealed test chamber; the display circuit is provided on the outer side surface of the body. The temperature and humidity detection circuit is used to detect the temperature and humidity in the test chamber where the relative humidity sensor is placed and display the detected temperature and humidity through the display circuit. In this way, a multi-chamber structure design can be realized based on the stable humidity characteristics of the saturated salt solution, and the calibration cost of the relative humidity can be reduced.

[0029] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given below in conjunction with the accompanying drawings and are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 Shows the schematic diagram of the disassembled structure of the handheld relative humidity calibrator based on saturated salt solution provided by the embodiments of the present invention;

[0032] Figure 2 Shows the schematic diagram of the sectional structure of the handheld relative humidity calibrator based on saturated salt solution provided by the embodiments of the present invention;

[0033] Figure 3 Shows the schematic diagram of the body structure provided by the embodiments of the present invention;

[0034] Figure 4 Shows the schematic diagram of the structure of the test chamber assembly provided by the embodiments of the present invention. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0036] The embodiments of the present invention provide a handheld relative humidity calibrator based on saturated salt solution, which will be described below through embodiments.

[0037] Figure 1 Shows the schematic diagram of the disassembled structure of the handheld relative humidity calibrator based on saturated salt solution provided by the embodiments of the present invention;

[0038] Figure 2 Shows the schematic diagram of the sectional structure of the handheld relative humidity calibrator based on saturated salt solution provided by the embodiments of the present invention;

[0039] Figure 3 Shows the schematic diagram of the body structure provided by the embodiments of the present invention;

[0040] Figure 4 Shows the schematic diagram of the structure of the test chamber assembly provided by the embodiments of the present invention.

[0041] Such as Figures 1 to 4As shown in the figure, in the embodiment of the present invention, the handheld relative humidity calibrator includes: a salt tank 11, a body 12, a measurement and control circuit 13, a lithium battery pack 14, a test chamber assembly 15, a base 16, and a sensor sealing and locking device 17. Among them, the salt tank 11 is a hollow columnar body with a sealed bottom and an external thread provided on the outer side of the top;

[0042] The body 12 is provided with a hollow and independent first chamber 121 and a second chamber 122. At a predetermined distance upward from the bottom end of the first chamber 121, a through hole is provided. On the inner side wall of the through hole, an internal thread matching the external thread provided on the top of the salt tank is provided. On the inner side wall of the top, a stepped groove is provided, and a screw hole for positioning is provided at the top end. The bottom of the second chamber 122 is sealed;

[0043] The measurement and control circuit 13 includes a temperature and humidity detection circuit and a display circuit 123;

[0044] The lithium battery pack 14 is connected to the measurement and control circuit 13 to provide power for the measurement and control circuit 13. The measurement and control circuit 13 is placed on the top of the second chamber 122 and fixed in the second chamber 122 through the top of the second chamber 122;

[0045] The test chamber assembly 15 is a hollow columnar body with a sealed bottom. A through groove 1511 for gas diffusion is provided on the outer side of the middle part. A liquid separation and breathable membrane 152 is attached to the outer side of the middle part. A convex platform 1512 with a middle protrusion is provided at the top. An external thread is provided on the outer side above the convex platform 1512;

[0046] The test chamber assembly 15 is placed into the first chamber 121. The convex platform 1512 is lapped on the stepped groove and seals the stepped groove. The space of the first chamber 121 under the stepped groove and the space of the salt tank 11 form a saturated salt solution storage chamber;

[0047] The base 16 is provided with a screw hole at the top corresponding to the position of the screw hole provided at the top of the body 12. The screw hole of the base 16 and the screw hole provided at the top of the body 12 are fixed to connect the base 16 and the body 12 through screws. A through hole matching the size above the convex platform of the test chamber assembly 15 is provided corresponding to the position where the first chamber 121 is provided in the body;

[0048] The sensor sealing and locking device 17 is used to seal and lock the relative humidity sensor placed in the hollow columnar body of the test chamber assembly in combination with the external thread provided on the outer side above the convex platform 1512. The sensor sealing and locking device 17 forms a sealed test chamber with the space in the hollow columnar body of the test chamber assembly 15;

[0049] The display circuit is provided on the outer side of the body 12. The temperature and humidity detection circuit is used to detect the temperature and humidity in the test chamber where the relative humidity sensor is placed and display the detected temperature and humidity through the display circuit 123.

[0050] In an embodiment of the present invention, as an alternative embodiment, the external thread size provided on the outer side of the top of the salt shaker is: M35X1.5. The lithium battery pack is powered and charged through a TYPE-C interface.

[0051] In an embodiment of the present invention, as an alternative embodiment, the sensor sealing and locking device includes: a boss fixed cover 171, an adjustable locking unit 172, and an end cover 173. Among them, the boss fixed cover 171 includes a first boss and a second boss, and the size of the first boss is larger than that of the second boss. Among them, on the inner side surface of the first boss, an internal thread is provided that matches the external thread provided on the outer side surface above the boss, and on the inner side surface of the second boss, an internal thread is provided, and on the outer side surface of the second boss, an external thread is provided;

[0052] The adjustable locking unit 172 is a hollow cylinder, wider at the top and narrower at the bottom. Uniformly spaced opening grooves are provided at the upper part, and an external thread that matches the internal thread provided on the inner side surface of the second boss is provided on the outer side surface of the lower part;

[0053] The end cover 173 is a hollow cylinder, and an internal thread that matches the external thread provided on the outer side surface of the second boss is provided on the inner side surface.

[0054] In an embodiment of the present invention, after the relative humidity sensor is placed in the test chamber through the end cover, the adjustable locking unit, and the boss fixed cover, by using the internal thread provided on the inner side surface of the second boss, screw it into the external thread provided at the lower part of the adjustable locking unit, so that the uniformly spaced opening grooves at the upper part of the adjustable locking unit gradually tighten, thereby compressing the hollow space until the adjustable locking unit is in close contact with the relative humidity sensor, forming a scalable interface. Thus, by using the sensor sealing and locking device, relative humidity sensors with different sizes (13 - 18 mm outer diameter) can be placed in the test chamber, and the relative humidity sensor can be sealed and locked, so that it can be applicable to the calibration of various types of relative humidity sensors, with wide applicability.

[0055] In an embodiment of the present invention, as an alternative embodiment, the upper part size of the adjustable locking unit is smaller than the size of the second boss.

[0056] In an embodiment of the present invention, as an alternative embodiment, it further includes:

[0057] The sealing cover 18 has an internal thread provided on the inner side that matches the external thread provided on the outer side surface above the boss 1512. After the relative humidity sensor is removed from the test chamber and the sensor sealing and locking device is removed, screw it to seal the opening of the test chamber assembly 15.

[0058] In an embodiment of the present invention, as an alternative embodiment, an O-ring is further included, which is sleeved on the external thread of the salt pot and seals the salt pot when mating with the internal thread provided on the inner side wall of the first chamber. Thus, during use, it is convenient to connect to various structural components of the humidity calibrator, and it can also be used to seal the humidity calibrator with a sealing cover when not in use.

[0059] In an embodiment of the present invention, as an alternative embodiment, the test chamber assembly includes: a cylindrical hollow stainless steel column bracket 151 and a liquid-separating and breathable membrane 152 attached to the outer side surface of the stainless steel column bracket 151. Among them,

[0060] The outer side surface of the stainless steel column bracket 151 is provided with evenly distributed through grooves 1511 for air permeability, the bottom is sealed, and the top is provided with a boss 1512 protruding in the middle. The stainless steel column bracket 151 is inserted into the salt pot 11, forming a reserved space with the bottom of the salt pot 11. The lower part of the boss 1512 forms a seal with the salt pot 11, and the outer side surface of the upper part of the boss 1512 is provided with an external thread.

[0061] In an embodiment of the present application, as an alternative embodiment, the stainless steel column bracket includes: a bracket base, a stainless steel body, and a bracket top cover. Among them,

[0062] The bracket base is fixed to the bottom of the stainless steel body, sealing the stainless steel body;

[0063] A first hollow space is formed inside the stainless steel body, and evenly distributed through grooves are provided on the outer side surface. The liquid-separating and breathable membrane is attached to the outer side surface of the stainless steel column;

[0064] A second hollow space with the same inner diameter as the first hollow space is formed inside the bracket top cover. The bottom is sealed and connected to the salt pot, and the top is sealed and connected to the stepped groove.

[0065] In an embodiment of the present application, as an alternative embodiment, the bracket top cover includes: a bracket first boss, a bracket second boss, and a bracket third boss. The bracket first boss, the bracket second boss, and the bracket third boss are integrally formed. Among them, an annular groove is provided in the middle of the outer side of the bracket first boss, and a silica gel sealing sleeve is placed in the annular groove. The bracket first boss is tightly inserted into the salt pot;

[0066] The size of the bracket second boss is the same as that of the salt pot;

[0067] The outer side surface of the bracket third boss is provided with an external thread.

[0068] In an embodiment of the present application, the inner side surfaces of the bracket first boss, the bracket second boss, and the bracket third boss are smooth inner surfaces, and the tight insertion includes, but is not limited to, interference fit and press fit.

[0069] In an embodiment of the present invention, as an alternative embodiment, the first chamber includes: a saturated salt solution storage chamber and a test chamber.

[0070] Among them,

[0071] The saturated salt solution storage chamber (salt tank chamber) and the test chamber are arranged coaxially and in opposite directions.

[0072] In an embodiment of the present invention, the salt tank chamber is used to place canned saturated salt solution, and the test chamber is used to place a relative humidity sensor for calibration.

[0073] In an embodiment of the present invention, as an alternative embodiment, a plurality of different types of salt tanks are provided, and each salt tank corresponds to a saturated salt solution with a humidity value, so as to construct a mapping relationship table between temperature and humidity and salt tank types. For example, in the mapping relationship table, six different types of salt tanks are provided. Among them, salt tank type one is potassium acetate saturated salt solution, and the standard relative humidity value is 23.11 ± 0.25%; salt tank type two is magnesium chloride saturated salt solution, and the standard relative humidity value is 33.07 ± 0.18%; salt tank type three is potassium carbonate saturated salt solution, and the standard relative humidity value is 43.16 ± 0.33%; salt tank type four is sodium bromide saturated salt solution, and the standard relative humidity value is 59.14 ± 0.44%; salt tank type five is sodium chloride saturated salt solution, and the standard relative humidity value is 75.47 ± 0.14%; salt tank type six is potassium chloride saturated salt solution, and the standard relative humidity value is 85.11 ± 0.29%. The above standard values are all at 20°C. For standard values at other temperatures, please refer to relevant standard materials and will not be elaborated here. In the present invention, a relative humidity sensor with an accuracy less than or equal to ±1.5%RH is provided in the test chamber. After the calibrator is powered on, the measurement and control circuit will automatically collect the temperature and relative humidity values of the relative humidity sensor, and judge the salt tank type through the following algorithm: based on the collected temperature, determine the standard relative humidity value corresponding to each type of salt tank at this temperature, and then compare the collected humidity value with the six standard relative humidity values corresponding to this temperature in turn. When the absolute value of the difference between this value and a certain standard relative humidity value is less than 3%, the current corresponding salt tank type is judged based on this standard relative humidity value. For example, if the collected temperature is 20°C and the collected relative humidity value is 23%, it can be determined that the inserted salt tank type is potassium acetate saturated salt solution.

[0074] In an embodiment of the present invention, the external thread dimensions of different salt tanks are the same, so that salt tanks with different humidity values can be replaced.

[0075] In an embodiment of the present invention, as another alternative embodiment, it further includes:

[0076] A fan, which is arranged inside the test chamber assembly and is a micro axial flow forced agitation fan, is used to forcibly agitate and diffuse the gas that evaporates from the saturated salt solution storage area of the salt tank and diffuses into the test chamber through the liquid separation and air permeable membrane.

[0077] In the embodiment of the present invention, the lithium battery pack drives the fan to rotate, and the fan can be turned on and off regularly according to the settings of the corresponding screen of the display circuit. As an alternative embodiment, the fan is arranged at the indoor bottom of the test chamber, and ventilation slots for diffusion are provided on the side of the test chamber, which are connected to the salt tank chamber through the overnight air permeable membrane, so as to exchange and integrate with the gas in the salt tank filled with saturated salt solution, realizing the rapid stability of the relative humidity and temperature in the test chamber and reducing the test error.

[0078] In the embodiment of the present invention, by using the fan, the gas evaporated from the saturated salt solution storage area of the salt tank can quickly diffuse into the test chamber through the liquid separation and air permeable membrane, so that the environment in the test chamber can be quickly stabilized and the purpose of the standard test environment of the relative humidity sensor can be achieved.

[0079] In the embodiment of the present invention, as an alternative embodiment, the measurement and control circuit is also used to query the pre-set mapping relationship table of temperature and humidity and salt tank type according to the temperature and humidity monitored in the test chamber in real time, identify the type of salt tank inserted in the saturated salt solution storage area, and query the pre-set look-up table of temperature, salt tank type and standard relative humidity according to the monitored current temperature and the identified salt tank type, so as to obtain the standard relative humidity corresponding to the current temperature and salt tank type. According to the queried standard relative humidity and the relative humidity value calibrated by the relative humidity sensor at this temperature, the relative humidity sensor is calibrated, so as to achieve the purpose of quickly, stably and accurately providing the standard relative humidity, and it can be applied to environments with high humidity such as 98%RH or low humidity of 11%RH.

[0080] In the embodiment of the present invention, as an alternative embodiment, after identifying the type of the inserted salt tank, the identified salt tank type is displayed through the display circuit. As another alternative embodiment, after identifying the type of the inserted salt tank, if the current temperature exceeds the temperature range corresponding to the salt tank type, an alarm is triggered. Among them, the display circuit includes but is not limited to: liquid crystal display (LCD), light emitting diode (LED), organic light emitting diode (OLED). In the embodiment of the present invention, the display circuit can alternately display the test interface and the battery circuit interface.

[0081] Table 1 is a schematic diagram of the look-up table of the standard relative humidity corresponding to a certain type of salt tank.

[0082] Table 1

[0083] ℃ °F %RH 10 50 86.77 15 59 85.92 20 68 85.11 25 77 84.34 30 86 83.62 35 95 82.95

[0084] In the embodiment of the present invention, the measurement and control circuit realizes measurement and control through a microcontroller unit (MCU, Microcontroller Unit). As an alternative embodiment, it includes: an MCU, a collection circuit, and a clock circuit. Among them,

[0085] The clock circuit includes: a battery, a first capacitor, a second capacitor, and a clock chip. Among them,

[0086] The negative electrode of the battery is grounded, and the positive electrode is respectively connected to the battery pin (BBAT) of the clock chip and one end of the first capacitor;

[0087] One end of the second capacitor is connected to the power supply pin (VCC) of the clock chip;

[0088] The other end of the first capacitor and the other end of the second capacitor are respectively grounded;

[0089] The data pin (SDA) of the clock chip is connected to the PB7 pin (pin 43) of the MCU, the clock pin (SCL) is connected to the PB6 pin (pin 42) of the MCU, the reset pin (RST) is connected to the PB13 pin (pin 26) of the MCU, and the INT / SQW pin is connected to the PB12 pin (pin 25) of the MCU;

[0090] The collection circuit includes: a first resistor, a second resistor, and a trigger. Among them,

[0091] One end of the first resistor is respectively connected to one end of the second resistor and the first pin of the trigger;

[0092] The other end of the first resistor is respectively connected to the second pin of the trigger and the PB15 pin (pin 28) of the MCU;

[0093] The other end of the second resistor is respectively connected to the third pin of the trigger and the PB14 pin (pin 27) of the MCU;

[0094] The fourth pin of the trigger is grounded.

[0095] In the embodiment of the present invention, for the specific structures of the MCU, the clock chip, and the trigger, reference can be made to relevant technical documents.

[0096] In the embodiments of the present invention, based on the stable humidity characteristics of saturated salt solutions, a multi-chamber structure design is realized. A salt tank filled with saturated salt solution, a micro-automatic acquisition measurement and control circuit, a specific structure and chambers are adopted. Through forced air agitation and diffusion, the types of saturated salt solutions in the inserted salt tank are monitored in real time. By looking up a table, the corresponding standard relative humidity is obtained to calibrate the relative humidity sensor. Thus, on the basis of ensuring the calibration function of the relative humidity sensor, miniaturization of the device is achieved.

[0097] In the embodiments of the present invention, further, for high humidity and low humidity ranges, especially when there is a large difference between the ambient humidity and the measured humidity, due to reasons such as airtightness and water vapor partial pressure, it is difficult to reach the standard value, resulting in a large deviation. A micro fan is used for diffusion and convection, so that the ambient humidity and the measured humidity can reach equilibrium in a short time and reach the standard value. At the same time, an adjustable locking structure can be used to adapt to relative humidity sensors with different outer diameters.

[0098] In the embodiments provided in the present application, it should be understood that the disclosed system can be implemented in other ways. The system embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the system or unit can be in electrical, mechanical or other forms.

[0099] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, each functional unit in the embodiments provided in the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0101] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps described in various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0102] It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0103] Finally, it should be noted that: the above-mentioned embodiments are only specific implementation manners of this application, used to illustrate the technical solution of this application, rather than limiting it. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed in this application can still modify the technical solution described in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiments of this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A hand-held relative humidity calibrator based on a saturated salt solution, characterized in that, Comprising: A salt pot, a body, a measurement and control circuit, a lithium battery pack, a test chamber assembly, a base, and a sensor sealing and locking device. Among them, The salt pot is a hollow columnar body with a sealed bottom and an external thread provided on the outer side of the top; Inside the body, there are provided a hollow and mutually independent first chamber and a second chamber. At a predetermined distance upward from the bottom end of the first chamber, there is a through hole. On the inner side wall of the through hole, there is an internal thread matching the external thread provided on the top of the salt pot. On the inner side wall of the top, there is a stepped groove, and at the top, there is a screw hole for positioning. The bottom of the second chamber is sealed; The measurement and control circuit includes a temperature and humidity detection circuit and a display circuit; The lithium battery pack is connected to the measurement and control circuit to provide power for the measurement and control circuit. The measurement and control circuit and the lithium battery pack are placed and fixed in the second chamber through the top of the second chamber; The test chamber assembly is a hollow columnar body with a sealed bottom. On the outer side of the middle part, there is a through groove for gas diffusion. A liquid separation and breathable membrane is attached to the outer side of the middle part. At the top, there is a boss with a middle protrusion. On the outer side above the boss, there is an external thread; The test chamber assembly is placed into the first chamber. The boss overlaps on the stepped groove and seals the stepped groove. The space of the first chamber under the stepped groove and the space of the salt pot form a saturated salt solution storage chamber; The base has a screw hole at the top corresponding to the position of the screw hole provided at the top of the body. This screw hole and the screw hole provided at the top of the body are used to fixedly connect the base and the body through screws. Corresponding to the position where the first chamber is provided in the body, there is a through hole matching the size above the boss of the test chamber assembly; The sensor sealing and locking device is used to seal and lock the relative humidity sensor placed in the hollow columnar body of the test chamber assembly in combination with the external thread provided on the outer side above the boss. The sensor sealing and locking device and the space in the hollow columnar body of the test chamber assembly form a sealed test chamber; The display circuit is provided on the outer side of the body. The temperature and humidity detection circuit is used to detect the temperature and humidity in the test chamber where the relative humidity sensor is placed and display the detected temperature and humidity through the display circuit; The sensor sealing and locking device includes: a boss fixed cover, an adjustable locking unit, and an end cover. Among them, The boss fixed cover includes a first boss and a second boss. The size of the first boss is larger than that of the second boss. Among them, On the inner side of the first boss, there is an internal thread matching the external thread provided on the outer side above the boss. On the inner side of the second boss, there is an internal thread. On the outer side of the second boss, there is an external thread; The adjustable locking unit is a hollow columnar body with a wider upper part and a narrower lower part. The upper part is provided with evenly distributed and spaced opening grooves. On the outer side of the lower part, there is an external thread matching the internal thread provided on the inner side of the second boss; The end cover is a hollow columnar body. On the inner side, there is an internal thread matching the external thread provided on the outer side of the second boss; After the relative humidity sensor is placed in the test chamber through the end cap, the adjustable locking unit, and the boss fixing cover, the external thread provided at the lower part of the adjustable locking unit is screwed into the internal thread provided on the inner side surface of the second boss, so that the spaced open slots at the upper part of the adjustable locking unit are gradually tightened until the adjustable locking unit is in close contact with the relative humidity sensor.

2. The handheld relative humidity calibrator according to claim 1, characterized in that, The upper part of the adjustable locking unit is smaller in size than the second boss.

3. The handheld relative humidity calibrator according to claim 1 or 2, characterized in that, Further included is: A sealing cover, with an internal thread provided on the inner side thereof that mates with the external thread provided on the outer side surface above the boss. After the relative humidity sensor and the sensor sealing and locking device are removed from the test chamber, the opening of the test chamber assembly is screwed shut.

4. The hand-held relative humidity calibrator according to claim 1 or 2, characterized in that The test chamber assembly includes: A cylindrical hollow stainless steel column bracket and a liquid-separating and breathable membrane attached to the outer side surface of the stainless steel column bracket. Among them, evenly distributed through slots for ventilation are provided on the outer side surface of the stainless steel column bracket, the bottom is sealed, a boss protruding in the middle is provided at the top, the stainless steel column bracket is inserted into the salt tank, a reserved space is formed with the bottom of the salt tank, the lower part of the boss forms a seal with the salt tank, and an external thread is provided on the outer side surface of the upper part of the boss.

5. The handheld relative humidity calibrator according to claim 4, characterized in that, The stainless steel column bracket includes: A bracket base, a stainless steel body, and a bracket top cover. Among them, The bracket base is fixed to the bottom of the stainless steel body to seal the stainless steel body; A first hollow space is formed inside the stainless steel body, evenly distributed through slots are provided on the outer side surface, and the liquid-separating and breathable membrane is attached to the outer side surface of the stainless steel column; A second hollow space with the same inner diameter as the first hollow space is formed inside the bracket top cover, the bottom is hermetically connected to the salt tank, and the top is hermetically connected to the stepped groove.

6. The handheld relative humidity calibrator according to claim 1 or 2, characterized in that, The first chamber includes: A saturated salt solution storage chamber and a test chamber. Among them, The saturated salt solution storage chamber and the test chamber are arranged coaxially and in opposite directions.

7. The hand-held relative humidity calibrator according to claim 1 or 2, characterized in that, Further included is: A fan, arranged inside the test chamber assembly, which is a micro axial flow forced agitation fan, used to forcibly agitate and diffuse the gas that evaporates from the saturated salt solution storage area of the salt tank and diffuses into the test chamber through the liquid-separating and breathable membrane.

8. The handheld relative humidity calibrator according to claim 1 or 2, wherein The measurement and control circuit monitors the temperature and humidity inside the test chamber in real time. Based on the monitored temperature and humidity, it queries the pre-set mapping relationship table between temperature and humidity and salt tank types, identifies the type of salt tank inserted in the saturated salt solution storage area, and based on the monitored current temperature and the identified salt tank type, queries the pre-set look-up table of temperature, salt tank type and standard relative humidity to obtain the standard relative humidity corresponding to the current temperature and salt tank type. Based on the queried standard relative humidity and the relative humidity value calibrated by the relative humidity sensor at this temperature, the relative humidity sensor is calibrated.

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