JPH11148696A - Temperature and humidity controller of environment testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the control accuracy of the temperature and humidity of an environment testing device by improving the measuring accuracy of the relative humidity. SOLUTION: A relative humidity measuring instrument 2 is constituted by arranging a relative humidity element 21 and a temperature element 22 in a test chamber 1 and connecting the elements 21 and 22 to an amplifier box 23 on the outside of the chamber 1 through a probe 24 and a temperature sensor 3 is provided near the instrument 2. The control outputs of an environmental testing device 100 to a heater 12 and a humidifier 13 are generated by using corrected relative humidity and the temperature detected by means of the sensor 3 by inputting the detected values of the instrument 2 and sensor 3 to the calculating section 41 of a temperature-humidity controller 4 and correcting the detected relative humidity with the detected value of the sensor 3. Therefore, even when a temperature difference exists between the inside and outside of the chamber 1 and the atmospheric temperature in the detecting section fluctuates due to the heat transferred from the probe 24 and amplifier section 23, the temperature and humidity of the environmental testing device can be controlled with high accuracy by obtaining accurate temperature and humidity values. In addition, the testing device can be applied over wide ranges of temperatures and humidities and the influence of the detecting sections on samples, etc., when the wind speed increases can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature and humidity control device for an environmental test apparatus having a test room in which temperature and humidity are controlled in a main body surrounded by a heat insulating wall.

[0002]

2. Description of the Related Art As a temperature and humidity control device of an environmental test device, a device using a relative hygrometer as shown in FIG. 3 for controlling temperature and humidity is conventionally known. The relative humidity meter 2 has a humidity sensing element 21 and a temperature sensing element 22 such as a thermistor attached to a tip portion located in a test chamber 1 of an environmental test apparatus. The measuring device is configured to convert the relative humidity and the temperature into electric signals at the attached amplifier box 23 and output the relative humidity and the temperature, and these signals can be used for temperature and humidity control. The tip and the amplifier are connected by a probe 24. By arranging the amplifier outside the test chamber in this way, there is an advantage that the humidity sensor can withstand a wide range of temperatures.

However, depending on the shape and material of the probe 24, heat transfer occurs between the indoor element and the outdoor amplifier, depending on the thermal conductivity and the heat capacity of the probe 24. The temperature does not become the original correct temperature, and a temperature difference occurs between the room and the room in the vicinity of the element portion, which is the same as the original correct temperature. Therefore, when the room temperature is high,
Heat is radiated from the element part to the outside through the probe and the amplifier part, so that the temperature of the element part falls below the nearby room temperature and the relative humidity is measured higher than the original correct value, while when the room is low temperature In addition, the temperature of the element section rises above the nearby temperature due to heat transfer from the outside, and the relative humidity is measured below a correct value. This tendency increases as the wind speed of the element section decreases.

As a result, there has been a problem that a measurement error occurs in the relative humidity and the temperature, and the accuracy of the temperature and humidity control of the environmental test apparatus is reduced. In this case, when the wind speed of the element portion is increased, the temperature of that portion approaches the original correct temperature and the accuracy of the measurement is improved, but the stress due to the wind speed applied to the object to be tested in the test room increases, This also promotes mechanical deterioration of the element portion.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art and improves the measurement accuracy without increasing the stress applied to the DUT and promoting the mechanical deterioration of the temperature / humidity detector. It is another object of the present invention to provide a temperature and humidity control device of an environmental test device capable of accurately controlling a wide range of temperature and humidity conditions.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to control the temperature and humidity of an environmental test apparatus having a temperature and humidity controlled test chamber in a main body surrounded by a heat insulating wall. A first device for measuring temperature and relative humidity in an apparatus
A detecting unit disposed at a measuring position in the main body, a converting unit disposed outside the main body, and converting a detection value detected by the detecting unit into an electric signal; and the converting unit and the detecting unit. A first measuring unit having a connection unit for connecting the unit and the second unit, a second measuring unit arranged near the measurement position and measuring the temperature in the vicinity, and heated or cooled among the state variables of the humid air. A calculation unit that corrects the relative humidity at the temperature to the nearby temperature by using a state variable that keeps a substantially constant value sometimes and calculates a corrected relative humidity, and a control condition including the corrected relative humidity and the nearby temperature. Adjusting means having an output unit for generating a control output.

[0007]

FIG. 1 shows an example of the overall configuration of a temperature and humidity control device of an environmental test apparatus to which the present invention is applied.
The temperature and humidity control device of the environmental test device forms a part of an environmental test device 100 including a test chamber 1 in which temperature and humidity are controlled in a main body surrounded by a heat insulating wall 11, and measures temperature and relative humidity. Relative humidity meter 2 as first measuring means
It has a temperature sensor 3 as second measuring means, a temperature and humidity controller 4 as adjusting means, and the like.

Although not shown, an air-conditioning room surrounded by a heat insulating wall 11 is disposed adjacent to the inside of the main body of the environmental test apparatus 100 in the same manner as the test room 1. Evaporator, heater 12, cooled by the circuit,
A humidifying unit for diverting water vapor generated by the humidifier 13 and a circulating blower are appropriately provided.

The relative humidity meter 2 has a measurement position A above the test room 1 where air is blown from the air-conditioning room in the main body.
As a conversion unit including a humidity sensing element 21 and a temperature sensing element 22 as a detection unit disposed in the test chamber, and an amplification circuit disposed outside the test chamber 1 and converting a detection value detected by the detection unit into an electric signal. Box 23, probe 2 disposed through insulation wall 11 as a connection part connecting the conversion unit and the detection unit
4 and the like, and measures the relative humidity and temperature at the measurement position A.

As the relative hygrometer 2, for example, a type that converts the capacitance of the humidity-sensitive element 21 that changes according to the relative humidity into a current or a voltage is used. As the temperature sensing element 22, a thermistor or the like is used. These detectors are surrounded by a protective cap 25 having a hole so as to communicate with the test chamber.

The temperature sensor 3 is disposed near the measurement position A and measures the temperature at the vicinity position B. Positions A and B
Are near the same temperature, so that the measurement position A shows the original correct temperature without any heat influence by the relative hygrometer 2 conducting to the outside. This means that the temperature sensor 3 is measuring the temperature at the measurement position A.

The temperature and humidity controller 4 includes a calculation unit 41 and an output unit 4
2, a setting unit 43 and the like. The calculation unit 41 mediates a state variable that keeps a substantially constant value when heated or cooled among the state variables of the humid air, corrects the relative humidity at the temperature of the measurement position A to a nearby temperature, and calculates the corrected relative humidity. calculate. As the state variables to be mediated, absolute humidity, water vapor partial pressure, dew point temperature, wet bulb temperature, and the like are used.

That is, the detected temperature and relative humidity at the measurement position A are t ₁ and Φ ₁ , respectively, the intermediate state variables such as absolute humidity and partial pressure of water vapor are x, the measured temperature in the vicinity is t ₂ , and the corrected relative humidity is Φ _Assuming that ₂ , for example, t, Φ, x
In addition to stocking the relational expression and numerical table of in advance, x is first determined from the input t ₁ and Φ ₁ , and using this x,
Performing calculation for obtaining the [Phi ₂ from t ₂ to be inputted. Note that such a calculation method is merely an example, and other appropriate calculation methods can be used.

The output unit 42 generates a control output from control conditions including the corrected relative humidity Φ ₂ and the temperature t ₂ in the vicinity. That is, these φ ₂ and t ₂ , the set temperature ts and the set relative humidity Φs set by the setting unit 43 are input, and the output for controlling the heater 12 and the humidifier 13 based on the deviation between the measured value and the set value. Transmits Pd and Ph.

The temperature and humidity control device described above has the following operation. The sample to be tested is placed in the test chamber 1 of the environmental test apparatus 100, and various devices such as a heater, a humidifier, a refrigerator, and a circulating blower are operated. Once set, the temperature and humidity controller starts control. That is, the relative humidity Φ ₁ and the temperature t ₁ at the measurement position A are measured by the relative hygrometer ₂ , the nearby temperature t ₂ is measured by the temperature sensor 3, and these are sent to the calculation unit 41 of the temperature and humidity controller 4. .

At this time, if the outside of the environmental test apparatus is at room temperature and the setting section 43 has set high humidity conditions, for example, a temperature of 60 ° C. and a relative humidity of 95%, the humidity sensing element of the relative humidity meter 2 The heat of the atmosphere covering the temperature-sensitive element 21 and the temperature-sensitive element 22 is transmitted to the probe 24 and radiated from the amplifier box 23 to the outside, so that the temperature of the atmosphere becomes lower than the temperature of the test room in the vicinity. Assuming that such a temperature drop is 1 ° C., for example, the relative humidity meter detects a relative humidity higher than that in the test chamber 1 by about 4.5%.

The calculation unit 41 calculates the intermediate state variables x such as the absolute humidity and the partial pressure of water vapor from the temperature t ₁ and the relative humidity Φ ₁ thus detected. This x does not change even if the moist air in this portion is heated or cooled by heat transfer via the probe 24, and has almost the same value at the measurement position A and its vicinity. Therefore, the calculation unit 41 can calculate the correct corrected relative humidity Φ ₂ from the x and the actual temperature t ₂ in the test chamber 1 without thermal influence. Such a calculation process is represented, for example, on a Mollier diagram of moist air as shown in FIG.

The output unit 42 receives the corrected relative humidity Φ ₂ and the temperature t ₂ having high measurement accuracy, which have been corrected in this way, and outputs the heater 12 from the set temperature ts and the set relative humidity Φs.
And the control outputs Pd and Ph of the humidifier 13 are transmitted, so that the temperature and humidity in the test chamber 1 can be accurately controlled. In addition, since the measurement accuracy and the control accuracy are improved without increasing the wind speed at the measurement position A as described above,
The stress due to the wind speed on the object to be tested in the test room can be greatly reduced, and the mechanical deterioration of the element portion due to the wind speed can be prevented. Furthermore, restrictions on the selection of the shape and material of the probe 24 of the relative hygrometer 2 and the wind speed of the element section are eliminated, and the environmental test apparatus can cope with a wide range of environmental conditions.

In FIG. 1, the relative hygrometer 2 and the temperature sensor 3 are separately provided. However, by taking care that the temperature sensor is not thermally affected by the relative hygrometer, these are integrated. It is also possible to have a structure that can be handled.

[0020]

As described above, according to the present invention, since the conversion unit of the first measuring means is disposed outside the test room from the detection unit in the test room via the connection unit, the temperature in the test room can be reduced. Even if it is controlled to a wide range of environmental conditions from low temperature to low humidity, the electric circuit etc. of the conversion unit is not affected by such environmental conditions,
The first measuring means can be used under a wide range of environmental conditions.

Since the second measuring means is provided in the vicinity of the measuring position where the detecting section is disposed, when the temperature difference between the test chamber and the outside is large, the converting section disposed outside and the connecting section thereof are provided. Due to the heat transfer, even if the temperature of the detecting section becomes different from the actual temperature, the temperature at the originally correct measurement position can be measured by the second measuring means.

The calculating section of the adjusting section sets the relative humidity corresponding to the temperature measured by the first measuring section to a state in which the state variable of the humid air is maintained at a substantially constant value when heated or cooled, for example, absolute humidity. Since the correction relative humidity is calculated by correcting the temperature in the vicinity of the detection unit by mediating a variable, the relative humidity detection unit detects the influence of the temperature outside the test chamber from the conversion unit of the first measurement unit via the connection unit. When receiving, the correct relative humidity corrected to the actual correct temperature in the test chamber can be determined by calculation.

The output of the adjusting means generates a control output from control conditions including such an accurate corrected relative humidity and a temperature near and at an accurate measurement position. Humidity conditions can be controlled accurately.

As described above, according to the present invention, it is possible to use the conventional first measuring means for measuring temperature and humidity in an environment test apparatus in which the temperature and humidity change over a wide range and the environment becomes high to some extent. Even when there is a large temperature difference between the inside and the outside of the environmental test device and the detected temperature of the first measuring means is not the original correct temperature, the detected temperature is corrected using the detected temperature of the second measuring means. By calculating the correct relative humidity in this way and combining this with the correct detected temperature of the second detecting means, the temperature and humidity control with high accuracy as described above can be effectively used by effectively utilizing all the detected values of the detecting means. Can be.

In this case, the measurement accuracy and control accuracy can be improved without increasing the wind speed at the measurement position.
The stress due to the wind speed on the object to be tested in the test room can be greatly reduced, and the mechanical deterioration of the detection unit due to the wind speed can be prevented. Furthermore, restrictions on the selection of the shape and material of the connecting portion of the first measuring means, the wind speed of the detecting portion, and the like are eliminated, and the environmental test apparatus can be adapted to a wide range of environmental conditions.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a temperature and humidity control device of an environmental test apparatus to which the present invention is applied, wherein (a) shows an entire configuration, and (b) shows a state where a detection unit of (a) is enlarged. Show.

FIG. 2 is a curve diagram illustrating an example of a method of correcting a relative humidity.

FIG. 3 is an explanatory view showing a structure of a relative hygrometer part of a temperature and humidity control device of a conventional environmental test device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test room 2 Relative hygrometer (1st measuring means) 3 Temperature sensor (2nd measuring means) 4 Temperature / humidity controller (adjusting means) 11 Insulated wall 21 Humidity sensitive element (detection part) 22 Temperature sensitive element (detection part) 23 Amplifier Box (Conversion Unit) 24 Probe (Connection Unit) 41 Calculation Unit 42 Output Unit 100 Environmental Test Equipment A Measurement Position

Claims (1)

[Claims] 1. A temperature and humidity control device of an environmental test device having a test room in which temperature and humidity are controlled in a main body surrounded by a heat insulating wall, wherein a first measuring means for measuring temperature and relative humidity is provided. A detecting unit disposed at a measurement position in the main body, a converting unit disposed outside the main body and converting a detection value detected by the detecting unit into an electric signal, and the converting unit and the detecting unit. A first measurement unit having a connection unit to be connected, a second measurement unit arranged near the measurement position and measuring the temperature in the vicinity,
A calculating unit that corrects the relative humidity at the temperature to the nearby temperature by using a state variable that maintains a substantially constant value when heated or cooled among the state variables of the humid air, and calculates a corrected relative humidity. An adjusting unit having an output unit for generating a control output from a control condition including a relative humidity and a temperature in the vicinity thereof, and a temperature and humidity control device for an environmental test device.