A device and method for calibrating temperature sensors of a WBGT index meter

Abstract

The application discloses a kind of WBGT index instrument temperature sensor calibration device and method, the device includes first thermostat, second thermostat, standard thermostat and temperature measurement system, the WBGT index instrument being calibrated includes black ball temperature sensor, wet bulb temperature sensor and dry bulb temperature sensor, standard thermostat places the WBGT index instrument being calibrated and calibrates dry bulb temperature sensor, first thermostat calibrates black ball temperature sensor, and second thermostat calibrates wet bulb temperature sensor;First and second thermostat include thermostat cover, liquid thermostat tank, liquid circulating pump, liquid return pipe, liquid inlet pipe, liquid sampling pipe and heat preservation layer, thermostat cover includes test cavity, liquid flow interlayer, liquid inlet hole and liquid return hole, temperature value in test cavity is close to the temperature value of liquid thermostat tank consistent.The application can independently provide stable and uniform temperature field for black ball temperature sensor, wet bulb temperature sensor and dry bulb temperature sensor respectively.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of temperature measurement, and particularly relates to a WBGT index meter temperature sensor calibration device and method. BACKGROUND

[0002] The WBGT (Wet Bulb Globe Temperature) index is a basic parameter for indicating the thermal load of human body contacting the environment. The WBGT index meter measures the black globe temperature, the wet bulb temperature and the dry bulb temperature through the black globe temperature sensor, the wet bulb temperature sensor and the dry bulb temperature sensor respectively, and then calculates the WBGT index by a formula.

[0003] According to JJF 1407-2013 WBGT Index Meter Temperature Sensor Calibration Specification, the temperature calibration range of the wet bulb temperature sensor is 5℃-40℃, the temperature calibration range of the black globe temperature sensor is 20℃-120℃, and the temperature calibration range of the dry bulb temperature sensor is 10℃-60℃. When the temperature range of 5℃-60℃ is calibrated, the WBGT index meter and the standard thermometer are placed in the effective working space of the standard thermostat at the same time, after the temperature is stable, the indication values of the wet bulb temperature sensor, the black globe temperature sensor and the dry bulb temperature sensor are read through the display interface of the WBGT index meter, and then compared with the indication value of the standard thermometer to obtain the indication error of each sensor of the index meter. When the temperature range of 60℃-120℃ is calibrated, the black globe temperature sensor and the standard thermometer are placed in the thermostat at the same time, after the temperature is stable, the indication value of the black globe temperature sensor is compared with the indication value of the standard thermometer to obtain the indication error of the black globe temperature sensor.

[0004] Since the WBGT index instrument can not be used in the laboratory environment temperature, also can not be used in normal temperature environment, the measured environment temperature and humidity is the actual environment conditions used by the WBGT index instrument. It is well known that the environment temperature has a great influence on the measuring accuracy of the instrument, especially when the environment temperature reaches 30℃ or above, at this time the influence of the environment temperature on the measurement results can not be ignored, therefore it is necessary to ensure that the calibration results of the WBGT index instrument are calibrated at the actual environment temperature, so as to ensure that the calibration results are accurate and reliable. When the WBGT index instrument is actually used, its wet bulb temperature, black bulb temperature and dry bulb temperature are different. According to the definition, the dry bulb temperature is the temperature directly measured by the temperature sensor in the ambient air, that is, the environment temperature; the black bulb temperature is the temperature obtained by placing the temperature sensor in the middle of a black ball of a specified size, due to the effect of the black ball absorbing radiation heat, the black bulb temperature is much higher than the environment temperature, especially in the sun exposure environment, the black bulb temperature may be close to 120℃; the wet bulb temperature is the temperature obtained by wrapping the temperature sensor sensing part with a layer of special gauze for wet bulb, the gauze is soaked in pure water, due to the effect of water vapor evaporation taking away heat, the wet bulb temperature is lower than the environment temperature, for example, in the environment directly irradiated by sunlight, when the environment temperature is 40℃, the relative humidity is 20% to 95%, the wet bulb temperature is about 23.2℃ to 39.2℃, the black bulb temperature may reach 45℃ to 70℃ according to the intensity of sunlight radiation.

[0005] According to the calibration method of JJF 1407-2013 WBGT index instrument temperature sensor calibration specification, when the WBGT index instrument is calibrated in the temperature range of 5-60 DEG C, the WBGT index instrument is placed in the constant temperature box, and the temperature value provided by the constant temperature box is only the temperature calibration point required by the dry bulb temperature, that is, the environmental temperature value of the index instrument in actual use, and the standard constant temperature box cannot simultaneously provide the calibration points of the corresponding other wet bulb temperature and black bulb temperature under the dry bulb temperature (environmental temperature). For example, when the temperature regulation of the standard constant temperature box is 60 DEG C, only the calibration of the sensors of the WBGT index instrument at 60 DEG C calibration point is performed under the condition that the environmental temperature is 60 DEG C, and when the temperature regulation of the standard constant temperature box is 10 DEG C, only the calibration of the sensors of the WBGT index instrument at 10 DEG C calibration point is performed under the condition that the environmental temperature is 10 DEG C. For the measurement error of the wet bulb temperature sensor and the black bulb temperature sensor of the WBGT index instrument at 10 DEG C calibration point, the results obtained by the WBGT index instrument under the conditions of 60 DEG C environmental temperature and 10 DEG C environmental temperature are completely different. Therefore, if the natural wet bulb temperature and the black bulb temperature are calibrated according to the air temperature of the standard constant temperature box, the calibration method does not conform to the actual use, because in actual use, under a certain air temperature, the wet bulb temperature is lower than the air temperature, and the black bulb temperature is higher than the air temperature. When the temperature calibration range is 60-120 DEG C, the black bulb temperature sensor needs to be placed in the constant temperature tank for calibration, and at this time, the WBGT index instrument is calibrated under the normal temperature condition in the laboratory, and this calibration method is completely inconsistent with the high temperature environment in actual use, and cannot guarantee the effectiveness of the traceable quantity value of the WBGT index instrument under the high temperature condition. SUMMARY

[0006] The purpose of the present application is to solve the problems in the prior art, and provide a WBGT index instrument temperature sensor calibration device and method, which can independently provide stable and uniform temperature fields for the black bulb temperature sensor, the wet bulb temperature sensor and the dry bulb temperature sensor, and meet the demand of traceability of the WBGT index instrument under the actual use temperature condition.

[0007] In order to achieve the above purpose, one aspect of the present application provides a WBGT index instrument temperature sensor calibration device, which comprises a first constant temperature device, a second constant temperature device, a standard constant temperature box and a temperature measurement system,

[0008] The calibrated WBGT index instrument comprises a black bulb temperature sensor, a wet bulb temperature sensor and a dry bulb temperature sensor, the standard constant temperature box is used for placing the calibrated WBGT index instrument and calibrating the dry bulb temperature sensor, the first constant temperature device is used for calibrating the black bulb temperature sensor, and the second constant temperature device is used for calibrating the wet bulb temperature sensor;

[0009] The first constant temperature device comprises a first constant temperature sleeve, a first liquid constant temperature tank, a first liquid circulating pump, a first liquid return pipe, a first liquid inlet pipe, a first liquid sampling pipe and a first heat preservation layer, and the first constant temperature sleeve comprises a first test cavity, a first liquid flow interlayer and a first liquid inlet hole and a first liquid return hole in communication with the first liquid flow interlayer;

[0010] The first test cavity is used for placing a black ball temperature sensor, one end of the first liquid inlet pipe is connected with the first liquid inlet hole, the other end of the first liquid inlet pipe is connected with the outlet of the first liquid circulating pump, the first liquid return pipe is connected with the first liquid return hole, the other end of the first liquid return pipe is placed in the first liquid constant temperature tank, one end of the first liquid sampling pipe is connected with the inlet of the first liquid circulating pump, and the other end of the first liquid sampling pipe is placed in the first liquid constant temperature tank, the outer surfaces of the first constant temperature sleeve, the first liquid return pipe and the first liquid inlet pipe are provided with the first heat preservation layer, and the first liquid circulating pump is used for making the liquid medium in the first liquid constant temperature tank flow into the first liquid flow interlayer through the first liquid inlet pipe and flow back into the first liquid constant temperature tank through the first liquid return pipe;

[0011] The second constant temperature device comprises a second constant temperature sleeve, a second liquid constant temperature tank, a second liquid circulating pump, a second liquid return pipe, a second liquid inlet pipe, a second liquid sampling pipe and a second heat preservation layer, and the second constant temperature sleeve comprises a second test cavity, a second liquid flow interlayer and a second liquid inlet hole and a second liquid return hole in communication with the second liquid flow interlayer;

[0012] The second test cavity is used for placing a wet ball temperature sensor, one end of the second liquid inlet pipe is connected with the second liquid inlet hole, the other end of the second liquid inlet pipe is connected with the outlet of the second liquid circulating pump, one end of the second liquid return pipe is connected with the second liquid return hole, the other end of the second liquid return pipe is placed in the second liquid constant temperature tank, one end of the second liquid sampling pipe is connected with the inlet of the second liquid circulating pump, and the other end of the second liquid sampling pipe is placed in the second liquid constant temperature tank, the outer surfaces of the second constant temperature sleeve, the second liquid return pipe and the second liquid inlet pipe are provided with the second heat preservation layer, and the second liquid circulating pump is used for making the liquid medium in the second liquid constant temperature tank flow into the second liquid flow interlayer through the second liquid inlet pipe and flow back into the second liquid constant temperature tank through the second liquid return pipe;

[0013] The temperature measuring system comprises a temperature measuring instrument and first, second and third standard thermometers connected with the temperature measuring instrument, and the first, second and third standard thermometers are respectively used for measuring the temperature values of the first liquid constant temperature tank, the second liquid constant temperature tank and the constant temperature box.

[0014] Another aspect of the present application provides a WBGT index meter temperature sensor calibration method, which calibrates the WBGT index meter to be calibrated by using the above-mentioned device, comprising:

[0015] Placing the measurement end of the WBGT index meter to be calibrated and the third standard thermometer in a standard thermostat, placing the measurement end of the first standard thermometer in a first liquid thermostat, placing the measurement end of the second standard thermometer in a second liquid thermostat, placing the black ball temperature sensor in the first test cavity, and placing the wet ball temperature sensor in the second test cavity;

[0016] Setting the temperature values of the standard thermostat, the first liquid thermostat and the second liquid thermostat as temperature calibration points, respectively, and measuring the temperature values of the first liquid thermostat, the second liquid thermostat and the thermostat by using the first standard thermometer, the second standard thermometer and the third standard thermometer, respectively;

[0017] Setting the temperature indications of the first standard thermometer, the second standard thermometer and the third standard thermometer as T 141 , T 142 and T 143 , respectively, and setting the temperature indications of the black ball temperature sensor, the wet ball temperature sensor and the dry ball temperature sensor as T 21 , T 22 and T 23 , respectively, calculating the error values as follows to complete the calibration of the black ball temperature sensor, the wet ball temperature sensor and the dry ball temperature sensor at the set temperature calibration points:

[0018] ΔT 21 = T 21 -T 141

[0019] ΔT 22 = T 22 -T 142

[0020] ΔT 23 = T 23 -T 143 ,

[0021] Wherein, ΔT 21 is the error value of the black ball temperature sensor, ΔT 22 is the error value of the wet ball temperature sensor, and ΔT 23 is the error value of the dry ball temperature sensor.

[0022] According to the WBGT index meter temperature sensor calibration device and method of the above-mentioned aspect of the present application, stable and uniform temperature fields can be respectively and independently provided for the black ball temperature sensor, the wet ball temperature sensor and the dry ball temperature sensor, thereby meeting the demand for tracing the temperature conditions of the WBGT index meter in actual use. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0024] Figure 1 This is a schematic diagram illustrating the working principle of the WBGT index instrument temperature sensor calibration device according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the WBGT index instrument being calibrated according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the first constant temperature device for calibrating the black ball temperature sensor according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the second constant temperature device for calibrating the wet-bulb temperature sensor according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the temperature measurement system according to an embodiment of the present invention;

[0029] Figure 6 This is a side view of the first and second thermostatic sleeves according to an embodiment of the present invention;

[0030] Figure 7 This is a front view of the first and second thermostatic jackets according to an embodiment of the present invention;

[0031] Figure 8 This is a cross-sectional schematic diagram of the first and second thermostatic jackets according to an embodiment of the present invention;

[0032] Figure 9 This is a top view schematic diagram of the first and second thermostatic jackets according to an embodiment of the present invention;

[0033] Figure 10 This is a bottom view of the first and second thermostatic sleeves according to an embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] One embodiment of the present invention provides a WBGT indexer temperature sensor calibration device, such as... Figure 1 As shown, the WBGT index instrument temperature sensor calibration device 1 of this embodiment of the invention is used to calibrate the WBGT index instrument 2 to be calibrated, and includes a first constant temperature device 11, a second constant temperature device 12, a standard constant temperature chamber 13 and a temperature measurement system 14.

[0036] like Figure 2 As shown, the WBGT index instrument 2 under calibration includes a black bulb temperature sensor 21, a wet bulb temperature sensor 22, and a dry bulb temperature sensor 23. The WBGT index instrument 2 under calibration may have a display unit for displaying the temperature values ​​of the black bulb temperature sensor 21, wet bulb temperature sensor 22, and dry bulb temperature sensor 23. A first temperature control device 11 is used to calibrate the black bulb temperature sensor 21, and a second temperature control device 12 is used to calibrate the wet bulb temperature sensor 22. The structures of the first temperature control device 11 and the second temperature control device 12 can be identical. Figure 3 As shown, the first temperature control device 11 of this embodiment includes a first temperature control jacket 111, a first liquid temperature control bath 112, a first liquid circulation pump 113, a first liquid return pipe 114, a first liquid inlet pipe 115, a first liquid sampling pipe 116, and a first insulation layer 117. Figure 4 As shown, the second constant temperature device 12 of this embodiment of the invention includes a second constant temperature jacket 121, a second liquid constant temperature bath 122, a second liquid circulation pump 123, a second liquid return pipe 124, a second liquid inlet pipe 125, a second liquid sampling pipe 126, and a second insulation layer 127.

[0037] The temperature measurement system 14 of this invention embodiment is as follows: Figure 5 As shown, the device includes a thermometer 144 and a first standard thermometer 141, a second standard thermometer 142, and a third standard thermometer 143 connected to the thermometer 144. The thermometer 144 can be a resistance thermometer. The first standard thermometer 141, the second standard thermometer 142, and the third standard thermometer 143 are used to measure the temperature values ​​of the first liquid constant temperature bath 112, the second liquid constant temperature bath 122, and the constant temperature chamber 13, respectively.

[0038] The structure of the first thermostatic jacket 111 of the first thermostatic device 11 and the second thermostatic jacket 121 of the second thermostatic device 12 is as follows: Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, among which Figure 1 The installation position in the middle is the reference surface. The first constant temperature sleeve 111 includes a first test chamber 1111, a first liquid flow jacket, and a first liquid inlet hole 1112 and a first liquid return hole 1113 communicating with the first liquid flow jacket.

[0039] The middle hollow part of the first constant temperature sleeve 111 is the first test cavity 1111. The black ball temperature sensor 21 of the WBGT index tester 2 is installed in the first test cavity 1111. One end of the first liquid inlet pipe 115 is connected with the first liquid inlet hole 1112 of the first constant temperature sleeve 111, and the other end of the first liquid inlet pipe 115 is connected with the outlet of the first liquid circulating pump 113. The first liquid return pipe 114 is connected with the first liquid return hole 1113, and the other end of the first liquid return pipe 114 is placed in the first liquid constant temperature tank 112. One end of the first liquid sampling pipe 116 of the first liquid circulating pump 113 is connected with the inlet position of the first liquid circulating pump 113, and the other end of the first liquid sampling pipe 116 is placed in the first liquid constant temperature tank 112. The outer surfaces of the first constant temperature sleeve 111, the first liquid return pipe 114 and the first liquid inlet pipe 115 are provided with the first heat preservation layer 117 made of heat preservation material, so that the whole medium circulating loop has good heat preservation performance. The first liquid circulating pump 113 makes the liquid medium with a specified temperature value in the first liquid constant temperature tank 112, such as silicon oil, water or alcohol, flow into the first liquid flow layer in the internal hollow structure of the first constant temperature sleeve 111 through the first liquid inlet pipe 115, and then flow back to the first liquid constant temperature tank 112 through the first liquid return pipe 114. The liquid medium is repeatedly circulated and flowed, so that the liquid medium with a constant temperature value quickly flows in the first liquid constant temperature sleeve 111, which can ensure that the first test cavity 1111 of the first constant temperature sleeve 111 has a stable and uniform temperature field in the temperature range of 5℃-120℃.

[0040] The second constant temperature sleeve 121 includes a second test cavity 1211, a second liquid flow layer, a second liquid inlet hole 1211 and a second liquid return hole 1213 connected with the second liquid flow layer.

[0041] The middle hollow part of the second constant temperature sleeve 121 is a second test cavity 1211. The wet bulb temperature sensor 22 of the calibrated WBGT index instrument 2 is arranged in the second test cavity 1211. One end of a second liquid inlet pipe 125 of the second constant temperature device 12 is connected with a second liquid inlet hole 1212, and the other end of the second liquid inlet pipe 125 is connected with an outlet of a second liquid circulating pump 123. One end of a second liquid return pipe 124 of the second constant temperature sleeve 121 is connected with a second liquid return hole 1213, and the other end of the second liquid return pipe 124 is arranged in the second liquid constant temperature tank 122. One end of a second liquid sampling pipe 126 is connected with an inlet position of the second liquid circulating pump 123, and the other end of the second liquid sampling pipe 126 is arranged in the second liquid constant temperature tank 122. The outer surfaces of the second constant temperature sleeve 121, the second liquid return pipe 124 and the second liquid inlet pipe 125 are provided with a second heat preservation layer 127 constructed by a heat preservation material, so that the entire medium circulating loop has good heat preservation performance. The second liquid circulating pump 123 causes liquid medium with a specified temperature value in the second liquid constant temperature tank 122, such as silicon oil, water or alcohol, to flow into a second liquid flow layer in the hollow structure inside the second constant temperature sleeve 121 through the second liquid inlet pipe 125. The liquid medium flows back to the second liquid constant temperature tank 122 through the second liquid return pipe 124, and the liquid medium repeatedly circulates and flows, so that the liquid medium with a constant temperature value quickly flows in the layer space of the second constant temperature sleeve 121, and the second test cavity 1211 of the second constant temperature sleeve 121 has a stable and uniform temperature field in a temperature range of 5℃ to 120℃.

[0042] The structures of the first constant temperature sleeve 111 and the second constant temperature sleeve 121 have the following characteristics:

[0043] (1) Size characteristics. In order to ensure that the black bulb temperature sensor 21 and the wet bulb temperature sensor 22 of the calibrated WBGT index instrument 2 have sufficient heat exchange with the corresponding first constant temperature sleeve 111 and second constant temperature sleeve 121, the inner diameter of the first test cavity 1111 of the first constant temperature sleeve 111 is as close as possible to the outer diameter of the black bulb temperature sensor 21, and the inner diameter of the second test cavity 1211 of the second constant temperature sleeve 121 is as close as possible to the outer diameter of the wet bulb temperature sensor 22. Because the space between the black bulb temperature sensor 21, the wet bulb temperature sensor 22 and the dry bulb temperature sensor 23 of the WBGT index instrument 2 is limited, the outer diameter of the first constant temperature sleeve 111 and the second constant temperature sleeve 121 is as small as possible. In the embodiment, the sizes (outer diameter mm x inner diameter mm x length mm) of the first constant temperature sleeve 111 and the second constant temperature sleeve 121 are Φ33.5 x Φ5.5 x 90, Φ34.5 x Φ6.5 x 90 and Φ35.5 x Φ7.5 x 90. The effective working area sizes (inner diameter mm x depth mm) in the test cavities are Φ5.5 x 80, Φ6.5 x 80 and Φ7.5 x 80.

[0044] (2) Structural features, such as Figure 3 As shown in FIG. 1, the internal space of the first constant-temperature sleeve 111 adopts a hollow structure and is to form a circulation loop with the corresponding first liquid constant-temperature tank 112, first liquid circulating pump 113, first liquid return pipe 114, first liquid inlet pipe 115 and liquid collection pipe 116, respectively, to ensure that the temperature medium of the first liquid constant-temperature tank 112 can flow quickly in the first constant-temperature sleeve 111 under the driving of the first liquid circulating pump 113; as shown in FIG. 1, the internal space of the second constant-temperature sleeve 121 adopts a hollow structure and is to form a circulation loop with the corresponding second liquid constant-temperature tank 122, second liquid circulating pump 123, second liquid return pipe 124 and second liquid inlet pipe 125, respectively, to ensure that the temperature medium of the second liquid constant-temperature tank 122 can flow quickly in the second constant-temperature sleeve 121 under the driving of the second liquid circulating pump 123. Figure 4

[0045] (3) Performance features, a first heat preservation layer 117 is constructed by using heat preservation materials for the first constant-temperature sleeve 111, first liquid return pipe 114 and first liquid inlet pipe 115, good heat preservation is performed on the liquid circulation loop of the first constant-temperature sleeve 111, influences on the air temperature in the standard constant-temperature box 13 caused by the first constant-temperature sleeve 111, first liquid return pipe 114 and first liquid inlet pipe 115 due to heat leakage are avoided, the temperature value in the first test cavity 1111 of the first constant-temperature sleeve 111 is ensured to be close to consistent with the temperature value of the corresponding first liquid constant-temperature tank 112, and the temperature field in the first test cavity 1111 is ensured to have temperature stability and uniformity meeting the calibration requirements. A second heat preservation layer 127 is constructed by using heat preservation materials for the second constant-temperature sleeve 121, second liquid return pipe 124 and second liquid inlet pipe 125, good heat preservation is performed on the liquid circulation loop of the second constant-temperature sleeve 121, influences on the air temperature in the standard constant-temperature box 13 caused by the second constant-temperature sleeve 121, second liquid return pipe 124 and second liquid inlet pipe 125 due to heat leakage are avoided, the temperature value in the second test cavity 1211 of the second constant-temperature sleeve 121 is ensured to be close to consistent with the temperature value of the corresponding second liquid constant-temperature tank 122, and the temperature field in the second test cavity 1211 of the second constant-temperature sleeve 121 is ensured to have temperature stability and uniformity meeting the calibration requirements.

[0046] ​Within a temperature range of 5℃ to 120℃, the temperature stability of the first test chamber 1111 of the first thermostatic sleeve 111 and the temperature uniformity of the second test chamber 1211 of the second thermostatic sleeve 121 can reach ±0.01℃. Within a temperature range of 5℃ to 60℃, the temperature uniformity can reach 0.01℃. Within a temperature range above 60℃ and below or equal to 120℃, the temperature uniformity can reach 0.03℃. (Since the inner diameter of the first test chamber 1111 of the first thermostatic sleeve 111 matches the outer diameter of the black bulb temperature sensor 21, its uniformity refers to the axial temperature difference of the first test chamber 1111 of the first thermostatic sleeve 111. Since the inner diameter of the second test chamber 1211 of the second thermostatic sleeve 121 matches the outer diameter of the wet bulb temperature sensor 22, its uniformity refers to the axial temperature difference of the second test chamber 1211 of the second thermostatic sleeve 121.)

[0047] Embodiments of the present invention also provide a WBGT index temperature sensor calibration method, wherein the WBGT index 2 to be calibrated is calibrated using the WBGT index temperature sensor calibration device 1 of the present invention.

[0048] First, according to Figure 1 As shown, the measuring ends of the WBGT index instrument 2 and the third standard thermometer 143 of the temperature measuring system 14 are placed in the effective working space of the standard constant temperature chamber 13. The measuring ends of the first standard thermometer 141 of the temperature measuring system 14 are placed in the effective working space of the first liquid constant temperature bath 112. The measuring ends of the second standard thermometer 142 of the temperature measuring system 14 are placed in the effective working space of the second liquid constant temperature bath 122. The first standard thermometer 141, the second standard thermometer 142, and the third standard thermometer 143 are all connected to the thermometer 144. At the same time, the black bulb temperature sensor 21 of the WBGT index instrument 2 is placed in the first test chamber 1111 of the first constant temperature sleeve 111, and the wet bulb temperature sensor 22 of the WBGT index instrument 2 is placed in the second test chamber 1211 of the second constant temperature sleeve 121.

[0049] Next, the temperatures of the standard constant temperature chamber 13, the first liquid constant temperature bath 112, and the second liquid constant temperature bath 122 are set as temperature calibration points and started. Simultaneously, the first liquid circulation pump 113, the second liquid circulation pump 123, the thermometer 144, and the WBGT index instrument 2 under calibration are started. After the actual temperatures of the constant temperature chamber 13, the first liquid constant temperature bath 112, and the second liquid constant temperature bath 122 reach the set values ​​and stabilize for a sufficient time, the first standard thermometer 141, the second standard thermometer 142, and the third standard thermometer 143 of the temperature measurement system 14 are used to measure the temperatures of the first liquid constant temperature bath 112, 112, and 122, respectively. 2. The temperature values ​​of the second liquid constant temperature bath 122 and the constant temperature chamber 13: Since the first constant temperature device 11 and the second constant temperature device 12 adopt good heat preservation measures, the heat loss of the liquid medium in the first liquid constant temperature bath 112 and the second liquid constant temperature bath 122 in the whole circulation loop is almost negligible. Therefore, the temperature value in the first test chamber 1111 of the first constant temperature sleeve 111 is equal to the measured value of the first standard thermometer 141 in the temperature measuring system 14, and the temperature value in the second test chamber 1211 of the second constant temperature sleeve 121 is equal to the measured value of the second standard thermometer 142 in the temperature measuring system 14.

[0050] Finally, let the temperature readings of the first standard thermometer 141, the second standard thermometer 142, and the third standard thermometer 143 in the temperature measurement system 14 be T respectively. 141 T 142 and T 143 The temperature readings of the black bulb temperature sensor 21, wet bulb temperature sensor 22, and dry bulb temperature sensor 23 of the WBGT index meter 2 are respectively T 21 T 22 and T 23 After the temperatures of the constant temperature chamber 13, the first liquid constant temperature bath 112 and the second liquid constant temperature bath 122 are sufficiently stable, the temperature readings of the first standard thermometer 141, the second standard thermometer 142, the third standard thermometer 143 and the black bulb temperature sensor 21, the wet bulb temperature sensor 22 and the dry bulb temperature sensor 23 of the WBGT index instrument 2 are read respectively. The error value is calculated by formulas (1), (2) and (3), that is, the calibration of the black bulb temperature sensor 21, the wet bulb temperature sensor 22 and the dry bulb temperature sensor 23 of the WBGT index instrument 2 at the corresponding temperature calibration point is completed under the ambient temperature (the same as the reading of the dry bulb temperature sensor 23).

[0051] ΔT 21 =T 21 -T 141 (1)

[0052] ΔT 22 =T 22 -T 142 (2)

[0053] ΔT 23 =T 23 -T 143 (3)

[0054] Where, ΔT 21 Let ΔT be the error value of the black ball temperature sensor. 22 The error value of the wet-bulb temperature sensor is ΔT. 23 This represents the error value of the dry-bulb temperature sensor.

[0055] Taking the calibration point of 120°C for the black bulb temperature sensor 21, the calibration point of 5°C for the wet bulb temperature sensor 22, and the calibration point of 60°C for the dry bulb temperature sensor 23 as examples, the calibration method of this embodiment of the invention will be further described in detail.

[0056] First, the measuring ends of the WBGT index instrument 2 and the third standard thermometer 143 of the temperature measuring system 14 are placed in the effective working space of the standard constant temperature chamber 13. The measuring end of the first standard thermometer 141 of the temperature measuring system 14 is placed in the first liquid constant temperature bath 112, and the measuring end of the second standard thermometer 142 of the temperature measuring system 14 is placed in the second liquid constant temperature bath 122. At the same time, the black ball temperature sensor 21 of the WBGT index instrument 2 is placed in the first test chamber 1111 of the first constant temperature sleeve 111. The first liquid inlet hole 1112 is connected to the first liquid circulation pump 113 through the first liquid inlet pipe 115. The first liquid sampling pipe 116 of the first liquid circulation pump 113 is placed in the first liquid constant temperature bath 112. The first liquid return hole 1113 is connected to the first liquid return pipe 114, and the other end of the first liquid return pipe 114 is placed in the first liquid constant temperature bath 112. The wet-bulb temperature sensor 22 of the WBGT index instrument 2 is placed in the second test chamber 1211 of the second thermostatic sleeve 121. The second liquid inlet 1212 is connected to the second liquid circulation pump 123 through the second liquid inlet pipe 125. The second liquid sampling pipe 126 of the second liquid circulation pump 123 is placed in the second liquid thermostatic bath 122. The second liquid return hole 1213 is connected to the second liquid return pipe 124. The other end of the second liquid return pipe 124 is placed in the second liquid thermostatic bath 122.

[0057] Next, the temperatures of the standard constant temperature chamber 13, the first liquid constant temperature bath 112, and the second liquid constant temperature bath 122 are set to 60℃, 120℃, and 5℃ respectively and started. At the same time, the thermometer 144, the WBGT index instrument 2, the first liquid circulation pump 113, and the second liquid circulation pump 123 are started. After the temperatures of the standard constant temperature chamber 13, the first liquid constant temperature bath 112, and the second liquid constant temperature bath 122 reach the set temperature values ​​and stabilize for 30 minutes, the temperature readings of the first standard thermometer 141, the second standard thermometer 142, and the third standard thermometer 143, as well as the temperature readings of the black bulb temperature sensor 21, the wet bulb temperature sensor 22, and the dry bulb temperature sensor 23 of the WBGT index instrument 2 are read and recorded respectively.

[0058] Finally, the temperature error is calculated using equations (1), (2) and (3) based on the recorded data, thus completing the calibration of the WBGT index instrument 2 at an air temperature of 60°C, with the calibration point of the black bulb temperature sensor 21 at 120°C, the calibration point of the wet bulb temperature sensor 22 at 5°C, and the calibration point of the dry bulb temperature sensor 23 at 60°C.

[0059] Using the above method, the black bulb temperature sensor 21, wet bulb temperature sensor 22, and dry bulb temperature sensor 23 of the WBGT indexer 2 are calibrated at other temperature calibration points, thus completing and realizing the calibration of the wet bulb temperature sensor, dry bulb temperature sensor, and black bulb temperature sensor of the WBGT indexer 2 under specified air temperature conditions.

[0060] According to the WBGT index meter temperature sensor calibration device and method of the present invention, an independent temperature field is provided for the WBGT index meter and its dry-bulb temperature sensor through a standard constant temperature chamber. Two sets of constant temperature devices provide two independent temperature fields for the WBGT index meter's black-bulb temperature sensor and wet-bulb temperature sensor, respectively. The temperature values ​​of the standard constant temperature chamber and the two liquid constant temperature baths are measured by a temperature measurement system. This allows for the provision of an independent temperature field with adjustable temperature within the range of 10℃ to 60℃ for the WBGT index meter (including the dry-bulb temperature sensor), an independent temperature field with adjustable temperature within the range of 20℃ to 120℃ for the black-bulb temperature sensor, and an independent temperature field with adjustable temperature within the range of 5℃ to 40℃ for the wet-bulb temperature sensor. This simultaneously and independently provides different temperature conditions for the black-bulb temperature sensor, the wet-bulb temperature sensor, and the WBGT index meter (including the dry-bulb temperature sensor), meeting the traceability requirements of the WBGT index meter under actual operating temperature conditions.

[0061] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A temperature sensor calibration device for a WBGT index meter, characterized in that, It includes a first temperature control device, a second temperature control device, a standard temperature control chamber, and a temperature measurement system. The WBGT index instrument to be calibrated includes a black bulb temperature sensor, a wet bulb temperature sensor, and a dry bulb temperature sensor. A standard constant temperature chamber is used to place the WBGT index instrument to be calibrated and to calibrate the dry bulb temperature sensor. A first constant temperature device is used to calibrate the black bulb temperature sensor, and a second constant temperature device is used to calibrate the wet bulb temperature sensor. The first constant temperature device includes a first constant temperature sleeve, a first liquid constant temperature bath, a first liquid circulation pump, a first liquid return pipe, a first liquid inlet pipe, a first liquid sampling pipe, and a first insulation layer. The first constant temperature sleeve includes a first test chamber, a first liquid flow jacket, and a first liquid inlet hole and a first liquid return hole that communicate with the first liquid flow jacket. The first test chamber is used to place the black ball temperature sensor. One end of the first liquid inlet pipe is connected to the first liquid inlet hole, and the other end of the first liquid inlet pipe is connected to the outlet of the first liquid circulation pump. The first liquid return pipe is connected to the first liquid return hole, and the other end of the first liquid return pipe is placed in the first liquid constant temperature bath. One end of the first liquid sampling pipe is connected to the inlet of the first liquid circulation pump, and the other end of the first liquid sampling pipe is placed in the first liquid constant temperature bath. The outer surfaces of the first constant temperature sleeve, the first liquid return pipe, and the first liquid inlet pipe are all provided with a first heat insulation layer. The first liquid circulation pump is used to make the liquid medium in the first liquid constant temperature bath flow into the first liquid flow jacket through the first liquid inlet pipe and flow back to the first liquid constant temperature bath through the first liquid return pipe. The second constant temperature device includes a second constant temperature sleeve, a second liquid constant temperature bath, a second liquid circulation pump, a second liquid return pipe, a second liquid inlet pipe, a second liquid sampling pipe, and a second insulation layer. The second constant temperature sleeve includes a second test chamber, a second liquid flow jacket, and a second liquid inlet hole and a second liquid return hole that are connected to the second liquid flow jacket. The second test chamber is used to house the wet-bulb temperature sensor. One end of the second liquid inlet pipe is connected to the second liquid inlet hole, and the other end of the second liquid inlet pipe is connected to the outlet of the second liquid circulation pump. One end of the second liquid return pipe is connected to the second liquid return hole, and the other end of the second liquid return pipe is placed in the second liquid constant temperature bath. One end of the second liquid sampling pipe is connected to the inlet of the second liquid circulation pump, and the other end of the second liquid sampling pipe is placed in the second liquid constant temperature bath. The outer surfaces of the second constant temperature sleeve, the second liquid return pipe, and the second liquid inlet pipe are all provided with a second heat insulation layer. The second liquid circulation pump is used to make the liquid medium in the second liquid constant temperature bath flow into the second liquid flow jacket through the second liquid inlet pipe and flow back to the second liquid constant temperature bath through the second liquid return pipe. The temperature measurement system includes a thermometer and a first standard thermometer, a second standard thermometer, and a third standard thermometer connected to the thermometer. The first standard thermometer, the second standard thermometer, and the third standard thermometer are used to measure the temperature values ​​of the first liquid constant temperature bath, the second liquid constant temperature bath, and the constant temperature chamber, respectively.

2. The apparatus as claimed in claim 1, characterized in that, The first insulation layer is used to insulate the liquid circulation loop of the first thermostatic jacket, so as to prevent the first thermostatic jacket, the first liquid return pipe and the first liquid inlet pipe from affecting the air temperature inside the standard thermostatic chamber due to heat leakage, ensuring that the temperature value inside the first test chamber is close to the temperature value of the first liquid thermostatic bath, and ensuring that the temperature field inside the first test chamber has temperature stability and uniformity that meet the calibration requirements. The second insulation layer is used to insulate the liquid circulation loop of the second thermostatic jacket, preventing the second thermostatic jacket, the second liquid return pipe, and the second liquid inlet pipe from affecting the air temperature inside the standard thermostatic chamber due to heat leakage. This ensures that the temperature value inside the second test chamber is close to the temperature value of the second liquid thermostatic bath, and that the temperature field inside the second test chamber has temperature stability and uniformity that meet the calibration requirements.

3. The apparatus as described in claim 2, characterized in that, The temperature stability of the first and second test chambers reaches ±0.01℃ within the temperature range of 5℃ to 120℃, the temperature uniformity reaches 0.01℃ within the temperature range of 5℃ to 60℃, and the temperature uniformity reaches 0.03℃ within the temperature range of above 60℃ and below or equal to 120℃.

4. The apparatus according to any one of claims 1-3, characterized in that, The inner diameter of the first test chamber is nearly identical to the outer diameter of the black bulb temperature sensor, and the inner diameter of the second test chamber is nearly identical to the outer diameter of the wet bulb temperature sensor.

5. The apparatus according to any one of claims 1-3, characterized in that, The liquid medium is silicone oil, water, or alcohol.

6. A method for calibrating a temperature sensor in a WBGT indexer, characterized in that, Calibrate the WBGT index instrument under test using the apparatus according to any one of claims 1-5, comprising: The measuring ends of the WBGT index instrument to be calibrated and the third standard thermometer are placed in a standard constant temperature chamber, the measuring end of the first standard thermometer is placed in a first liquid constant temperature bath, the measuring end of the second standard thermometer is placed in a second liquid constant temperature bath, the black bulb temperature sensor is placed in the first test chamber, and the wet bulb temperature sensor is placed in the second test chamber. The temperature values ​​of the standard constant temperature chamber, the first liquid constant temperature bath, and the second liquid constant temperature bath were set as temperature calibration points. The temperature values ​​of the first liquid constant temperature bath, the second liquid constant temperature bath, and the constant temperature chamber were measured by the first standard thermometer, the second standard thermometer, and the third standard thermometer, respectively. Let the temperature readings of the first, second, and third standard thermometers be T, respectively. 141 T 142 and T 143 The temperature readings of the black bulb temperature sensor, wet bulb temperature sensor, and dry bulb temperature sensor are T, respectively. 21 T 22 and T 23 The following calculations are performed to calibrate the black bulb temperature sensor, wet bulb temperature sensor, and dry bulb temperature sensor at the set temperature calibration points: ΔT 21 =T 21 -T 141 ΔT 22 =T 22 -T 142 ΔT 23 =T 23 -T 143 , Where, ΔT 21 Let ΔT be the error value of the black ball temperature sensor. 22 The error value of the wet-bulb temperature sensor is ΔT. 23 This represents the error value of the dry-bulb temperature sensor.

7. The method as described in claim 6, characterized in that, The temperatures of the standard constant temperature chamber, the first liquid constant temperature bath, and the second liquid constant temperature bath were set to 60℃, 120℃, and 5℃, respectively. The WBGT index instrument was calibrated with the black bulb temperature sensor at 120℃, the wet bulb temperature sensor at 5℃, and the dry bulb temperature sensor at 60℃ under an air temperature of 60℃.

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