JPS63214655A - Method for measuring humidity based on dry and wet bulb temperature measurement - Google Patents

Abstract

PURPOSE:To make exact measurement of humidity without disturbing the atmosphere in a space to be measured by introducing the atmosphere to be measured into the 2nd space without condensing the same, measuring the dry bulb temp. T>= and wet bulb temp. (t) in the 2nd space and determining the satd. steam pressure P1 of T2. CONSTITUTION:The temp. T1 in a test chamber 11 of constant temp. and constant humidity chamber 1 housing the atmosphere to be measured is measured by a temp. detecting end 2. Said atmosphere is introduced by a fan, etc., into the 2nd space 10. The 2nd space consists of an introducing duct 12 and a chamber 13 and is previously controlled to the temp. higher than the dew point by a temp. controller so as to prevent the condensation of the atmosphere introduced into the space. The dry bulb temp. T2 and wet bulb temp. (t) are measured by the dry bulb temp. detecting end 3 and wet bulb temp. detecting end 4 provided in the chamber 13. The relative humidity H1=(H2XO2)/P1 of the atmosphere to be measured is calculated from the satd. steam pressures P1, P2 of the water at the temps. T1, T2 and the relative humidity H2 of the atmosphere in the chamber 13 from the temps. T2, (t).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a humidity measuring method based on wet and dry bulb temperature measurements.

[Prior art and its problems]

In environmental test equipment such as thermostatic chambers and other fields where air conditioning is required, the humidity of the target space atmosphere is often measured based on wet and dry bulb temperature measurements.

Humidity measurement based on this dry-wet-bulb temperature measurement is performed by placing a dry-bulb temperature detection end and a wet-bulb temperature detection end directly in the space where the humidity is to be determined.

However, the dry-bulb temperature detection end and the wet-bulb temperature detection end are usually placed in separate areas where they do not get in the way; for example, in the case of a constant temperature incubator, they are placed right next to the gas outlet of an air conditioner. This generally makes it difficult to replace the wick in the wet bulb and replenish water (also, when moisture evaporates from the wet bulb, the spatial humidity is disturbed and low humidity is required). Furthermore, in the case of an atmosphere with a temperature below 0°C or above 100°C, humidity measurement cannot be performed even if the dry bulb temperature sensing end and wet bulb temperature sensing end are placed directly in the atmosphere. It can't be done.

Therefore, the purpose of the present invention is to make it easy to access the wick at the wet bulb temperature detection end, such as replacing the wick and replenishing water, so that the humidity in the atmosphere of the space where the humidity is to be determined is reduced by moisture from the wet bulb temperature detection end. It is an object of the present invention to provide a humidity measuring method based on psychrometric bulb temperature measurement, which is not disturbed by evaporation and is capable of measuring the relative humidity of the spatial atmosphere over a wide temperature range from low to high temperatures. .

Means for Solving Problem C] In other words, the present invention measures the temperature Tl of the atmosphere in the first space whose humidity is to be determined, and measures the temperature Tl of the atmosphere in the second space without condensing the atmosphere.
into a space, and measure the dry bulb temperature T2 and wet bulb temperature t of the introduced atmosphere using a dry bulb temperature detection end and a wet bulb temperature detection end arranged in the second space to determine the relative humidity H2 of the introduced atmosphere, The saturated water vapor pressure PI at the temperature Tl, the saturated water vapor pressure P2 at the temperature T2, and the relative humidity H
The present invention provides a humidity measuring method based on wet and dry bulb temperature measurement, which is characterized in that the first space atmospheric relative humidity H1%RH=(H2×P2)/PI is determined from 2.

In order to guide the first space atmosphere to the second space without causing dew condensation, if the temperature of the second space or the atmosphere already there is higher than the dew point of the first space atmosphere, it is sufficient to direct the atmosphere as it is,
Alternatively, the dew point may be forcibly maintained higher than the dew point.

(Example〕 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

This embodiment attempts to measure the humidity in a test chamber 11 of a constant temperature and humidity chamber 1, which is a type of environmental testing device. The thermostatic chamber 1 is equipped with an air conditioner (not shown).

The temperature Tl of the test chamber 11 is measured by a temperature detection end 2 which is known per se and placed there, while the atmosphere inside the test chamber 11 is introduced into the second space 10 by a suitable fan device or the like (not shown). . The second space includes an introduction duct or a vibrator 12 connected to the test chamber 11 and a chamber 13 connected thereto.
It consists of The temperature in the introduction duct or vibrator 12 and the chamber 13 connected thereto is adjusted to be higher than the dew point of the introduced atmosphere using an appropriate temperature control device (not shown) so that no condensation occurs in the introduced atmosphere.

In the chamber 13, a dry bulb temperature detection end 3 and a wet bulb temperature detection end 4 are arranged at positions that are in sufficient contact with the atmosphere introduced by the duct or the vibrator 12. The temperature inside the introduction duct or vibrator 12 and the room 13 is set several degrees higher than the wet bulb temperature detected by the wet bulb temperature detection @4. This is convenient because there is less water evaporation in the wet bulb, and the temperature inside the introduction duct or vibrator 12 and the chamber 13 connected to it are kept at the same temperature when the temperature Tl inside the test chamber 11 is below the freezing point. higher,
If it is above the boiling point of water, it should be lower than that, and in either case it should be adjusted within a range where no condensation occurs.

Thus, the temperature Tl in the test chamber 11 is known by the temperature detection end 2, and the dry bulb temperature T2 and wet bulb temperature t of the atmosphere in the chamber 13 are known by the dry bulb temperature detection end 3 and the wet bulb temperature detection end 4.

Once the dry bulb temperature T2 and the wet bulb temperature t are known, the relative humidity H2 of the atmosphere inside the room 13 is calculated using a calculation formula that is known per se.

Furthermore, the saturated vapor pressure P of water at the humidity temperature I in the test room lll
1. From the saturated vapor pressure P2 of water at the temperature T2 inside the chamber 13, the relative humidity H1 of the concave air inside the test chamber 11 is calculated using the following formula.

H1%RH-(H2×P2)/P 1 After measuring the dry bulb temperature and wet bulb temperature, is the gas in the second space IO discharged to the outside or guided to the air conditioner (not shown) of the constant temperature incubator? , or return it to the air conditioned room after dehumidification.

〔Effect of the invention〕

According to the present invention, the wet bulb temperature detection end can be installed in an appropriately selected space separate from the space where the humidity is to be determined, so that the wick at the wet bulb temperature detection end can be replaced, water can be replenished, etc. In addition, the humidity in the atmosphere of the space where the humidity is to be determined will not be disturbed by moisture evaporation from the wet bulb temperature detection end, and the temperature range of the space atmosphere from low to high temperatures can be widened. It is possible to measure the relative humidity of the atmosphere.

[Brief explanation of the drawing]

The drawing is for explaining the present invention in detail and is a schematic diagram of a constant temperature and humidity chamber. 1... Constant temperature and humidity chamber, 11... Test chamber, 10... Second space, 12... Duct or pipe, 13... Duct or chamber connected to vibrator 12 , 2...
...Temperature detection end, 3...Dry bulb temperature detection end, 4...Wet bulb temperature detection end. 1 ・ ・ ・ ・ 1 country onju! ! #/! ! Niji 11
・ ・ ・ ・Exam room 10... ・Second space 12...
・Duct Mata tt Nogu Eve T2 and Renna 4 Room 2...
Humidity narrow end 3... Rudder temperature skin detection end 4... Wet bulb humidity output end

Claims (1)

[Claims] (1) Temperature Tl of the atmosphere in the first space whose humidity is to be determined
is measured, and the atmosphere is guided to the second space without condensation,
A dry bulb temperature detection end and a wet bulb temperature detection end arranged in the second space measure the dry bulb temperature T2 and the wet bulb temperature t of the introduced atmosphere to determine the relative humidity H2 of the introduced atmosphere, and at the temperature Tl. Humidity based on wet and dry bulb temperature measurement, characterized in that the first space atmosphere relative humidity H1%RH=(H2×P2)/P1 is determined from the saturated water vapor pressure P1, the saturated water vapor pressure P2 at the temperature T2, and the relative humidity H2. Measuring method.