JPS5975144A - Output device of relative humidity - Google Patents

Abstract

PURPOSE:To find relative humidity with high accuracy, by using two temperature sensors converting a dry-bulb temperature and a wet-bulb temperature into electric signals and an arithmetic device inputting the signals of these temperature sensors. CONSTITUTION:An output D=100+5.24X{(t1-t2)<2>+66.29(t1-t2}/ (t2+18.01) is calculated by providing a thermistor RD outputting a dry-bulb temperature t1, a thermistor RW outputting a wey-bulb temperature t2, a subtraction circuit 1 calculating a=t1-t2, a multiplication circuit 2 calculating b=a<2>, an addition circuit 3 calculating c=t1+18.01, a multiplication circuit 4 calculating d=66.29Xa, an addition circuit 5 calculating f=b+d, a multiplication circuit 6 calculating g=5.24Xf, a division circuit 7 calculating h=g/c and an addition circuit 8 calculating i=100+h. The relative humidity is expressed by this output D within <=1.5% error all over the range of 5-30 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a relative humidity output device that uses a calculator to perform a relative humidity calculation formula for calculating relative humidity from dry bulb temperature and wet bulb temperature and outputs the result as an electrical signal. .

Conventional structure and its problems Conventionally, when determining relative humidity using wet and dry bulb temperature, water vapor pressure is required, so reading from the steam bath 9
This method requires a lot of work, is complicated, and has the disadvantage of being prone to errors.

Although relative humidity sensors exist, they lack reliability in terms of accuracy and life.

31\-゛Object of the Invention The present invention provides a complete relative humidity output device which eliminates the above-mentioned conventional drawbacks and can easily obtain highly accurate values without using a steam table in a computing unit.

Structure of the Invention The relative humidity output device of the present invention includes a first temperature sensor that converts dry bulb temperature into an electrical signal, a second temperature sensor that converts wet bulb temperature into an electrical signal, and With the signal of the temperature sensor as input, the following formula % formula % (When , the constant selected so that IRH-RHol≦y% in the specified temperature range, h-water vapor partial pressure [body Hg) h' -12 saturated steam pressure [: mmHg 1k constant number (1/2) + y-setting accuracy (%) hs = t, expressed as saturated steam pressure [NnHg] for all calculations and outputs as lHi electric signal. It consists of

Next, we will explain how to derive arithmetic expression A.

Figure 1 shows the relative humidity characteristics obtained by substituting the dry bulb temperature, wet bulb temperature, and water vapor temperature into Nikuchi and Ha.

In this case, Δt-1l-t2.

In this figure, RH=a4(Δ
t2+b4Δt)= The constant a 4. b 4 H-, a4 =
5.24. b+=66.29. From 2, RH=5.24(Δt2+66.29Δt)□E.

Next, t
By applying correction using the function of l, 5bem- can be found.

Therefore, the constant in equation A above is a 4 = 5.24 b 4 = 66.29 C4=18.01.

The column for people in Figure 3 is the relative humidity value calculated using the conventional method B, C formula and steam table, the column B is the relative humidity value calculated using the formula of the present invention, and the column C is the IA- This is the B10 value.

As shown in Figure 3, the relative humidity calculated using the formula is 6℃ ~
The relative humidity output device of the present invention is highly accurate, with a difference of less than 1.5% over the entire range of 30° C. and full realization of the equation.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, RD is a thermistor that outputs a dry bulb temperature value tlk as a first temperature sensor, RW is a thermistor 6l-2 that outputs a wet bulb temperature t2 as a second temperature sensor, and 1 digit a -t t t Z subtraction circuit, 2 is b=
Multiplication circuit that performs axa, 3 is an addition circuit that performs C-t1+18.01, 4 is d
= 66.29 x Multiplier circuit that performs a, 5 is f = b
6 is a multiplication circuit that performs g = 5.24 x f, 7 is a division circuit that performs h = g/c, and 8 is an addition circuit that performs 1 = 100 + h. A computing unit is configured.

Effects of the Invention The relative humidity output device of the present invention uses a fractional function calculation formula using wet and dry bulb temperature values as a variable, and easily outputs highly accurate relative humidity values directly from two measurement items of wet and dry bulb temperature. Furthermore, the circuit configuration for realizing the arithmetic expressions is also relatively simple.

Furthermore, since the measurement item required for the calculation is wet and dry bulb temperature, which is an important element as an environmental index, this method has the advantage of being directly applicable to air conditioning control.

[Brief explanation of drawings]

Figure 1 is a diagram of the relationship between wet and dry bulb temperature difference and relative humidity determined from Sprung's equation, Figure 2 is a circuit diagram showing an embodiment of the present invention, and Figure 3 is a comparison diagram of the accuracy of the calculation formula in the same circuit. It is. RD...Thermistor (first temperature sensor), RW
...Thermistor (second temperature sensor). Name of agent Patent attorney Toshio Nakao and one other person Procedural amendment January 72, 1988 1 Display of case 1986 Patent Application No. 186433 2 Name of invention Relative humidity output device 3 Person making amendment Case and Relationship between patent application
Appointment Address: 1006 Kadoma, Kadoma City, Osaka Prefecture
(582) Matsushita Electric Industrial Co., Ltd. Representative Toshihiko Yamashita 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Claims column 2 of the specification subject to the 6th amendment Page 6, Contents of amendment (1) The entire scope of the claims in the specification has been amended as per the attached sheet. (2) Amend the statement on page 3, line 12 of the specification. (3) Change “tl” to “t2” in Meiji 11th Book, page 3, line 16
Correct it as 1. 2. Claims: A first temperature sensor that converts dry bulb temperature into an electrical signal, a second temperature sensor that converts wet bulb temperature into an electrical signal, and signals from these first and second temperature sensors. When the total input is the following formula (%), the constant is selected so that IRH-RHOl≦y% in the specified temperature range, and the saturation for h'=t2 is the partial pressure of water vapor [: mynHq) Steam pressure [uuHglk = constant (v2), y - setting accuracy (%) hs = all calculations expressed as saturated steam pressure CaHql for t1, RHr
Relative humidity output device consisting of an arithmetic unit that outputs as an electrical signal.

Claims (1)

[Scope of Claims] A first temperature sensor that converts a dry bulb temperature into an electrical signal, a second temperature sensor that converts a wet bulb temperature into an electrical signal, and a system that converts the signals of these first and second temperature sensors. When the input is the following formula %)] []), the constant is selected so that IRH-RHol≦y% in the specified temperature range, and 21・-h-water vapor partial pressure [column Hg] Saturated vapor pressure Cwn Hg IIk for h'-12
A relative humidity output device comprising a computing unit that performs a calculation expressed as a constant number (1/2) + y - setting accuracy (も) hs = saturated steam pressure Cwn Hg with respect to t1, and outputs RH as an electrical signal.