JPH03138554A - Humidity measuring instrument - Google Patents

Abstract

PURPOSE:To eliminate the need for calibration which uses special equipment by providing a humidity detecting element, a temperature detecting element, a means which measures humidity and temperature from their outputs, and a means which discriminates whether the humidity exceeds a specific value or not. CONSTITUTION:The subject instrument is constituted of the humidity detecting element 1, an A/D converter 2 which converts its output signal into a digital signal, the temperature detecting element 3, an A/D converter 4 which converts its output signal into a digital signal, a CPU 5 which inputs digital signals from a them, a timer 6, a memory part 7, and a display part 8. The CPU 5 calculates the cumulative value of the continuance of a high-temperature and high-humidity state from the humidity and temperature measured by using the humidity detecting element 1 and temperature detecting element 3 and decides deterioration according to the cumulative value. Consequently, the deterioration can be recognized quantitatively and the humidity detecting element 1 can indicate its deterioration without using any special instrument. Further, the humidity detecting element 1 can be replaced within a permissible range and the humidity can be measured with an invariably small measurement error.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a humidity measuring device, and particularly to a humidity measuring device capable of outputting the amount of deterioration of a humidity detecting element.

(b) Conventional technology In general, resistance-type or capacitance-type temperature sensors are used as sensors (elements) in humidity measuring devices, and output signals according to resistance or capacitance values that change depending on humidity. Humidity is measured based on the signal.

However, when this type of humidity sensor is used at high temperatures for a long period of time, its characteristics change and measurement errors become large. Therefore, in the past, calibration was performed periodically using a humidity generation tank and a hygrometer for calibration, and if the measurement error was extremely large, the element was assumed to be deteriorated and replaced.

(c) Problems to be Solved by the Invention Conventional humidity measuring devices do not have a function to detect deterioration of the humidity detecting element, so as described above, a humidity generating tank and a hygrometer for calibration are used. Calibration had to be done periodically. Therefore, it is necessary to prepare equipment for calibration, and the calibration must be performed periodically, which is complicated.

Furthermore, there is a problem in that if the element deteriorates between calibrations and the next calibration, measurement errors occur during that period.

This invention has been made in view of the above-mentioned problems, and aims to provide a humidity measuring device that does not require calibration using special equipment by providing the detection device itself with a function to output the amount of deterioration. The purpose is

(d) Means and Effects for Solving the Problems The humidity measuring device of the present invention includes a humidity detecting element, a temperature detecting element, a means for measuring humidity and temperature based on the output of the element, and a humidity measuring device in which the measured humidity reaches a predetermined value. a means for determining whether the measured temperature exceeds a predetermined value; a means for determining whether the measured temperature exceeds a predetermined value; an accumulating means for accumulating the time during which the humidity and/or temperature exceeds a predetermined value; and means for outputting the cumulative value as the amount of deterioration.

This humidity measuring device determines whether or not the measured humidity and temperature exceed a predetermined value. For example, when the humidity and temperature exceed a predetermined value, the time during which the humidity and temperature have exceeded the predetermined value is accumulated, and the cumulative value is is output as the amount of deterioration. Therefore, humidity,
When the temperature exceeds a predetermined value, that is, when the high temperature and high temperature conditions continue, the time cumulative value becomes large and the amount of deterioration output becomes large. The degree of progress of deterioration can be determined from this amount of deterioration.

(E) Examples The present invention will be explained in more detail with reference to Examples below.

FIG. 1 is a block diagram showing the hardware configuration of a humidity measuring device in which the present invention is implemented. This humidity measuring device includes a humidity detecting element 1, an A/D converter 2 that converts an output signal of the humidity detecting element 1 into a digital signal, and a temperature detecting element 3.
, an A/D converter 4 that converts the output signal of the temperature detection element 3 into a digital signal, a CPU 5 that takes in the digital signal from the A/D converter 2.4, a timer 6, and a memory section 7. It is composed of a display section 8.

As the humidity detection element 1, for example, a resistance type humidity sensor is used. The CPU 5 uses the output signal of the humidity detection element 1 taken in via the A/D converter 2 and the output signal of the temperature detection element 3 taken in via the A/D converter 4 to generate a temperature-compensated humidity signal. It has a function to measure.

In a humidity sensor, if the continuous duration of a dew condensation state is defined as the amount of dew condensation, the amount of dew condensation becomes a type of stress and accelerates the progress of deterioration. In addition, the humidity sensor detects high temperatures, high temperatures [approximately 40
℃ or higher and 90% RH (relative humidity) or higher], the progress of deterioration is accelerated. Therefore, this example device has a function to determine the occurrence of dew condensation, measure the duration, and output the accumulated amount as the amount of deterioration, as well as a function to detect high temperature and high temperature state, and to accumulate the time at high temperature and high temperature. It has a function to output the cumulative value as the amount of deterioration. These two deterioration detection processes are executed by the CPU 5, and the data used during the execution is stored in the memory unit 7.

Although this embodiment has two deterioration detection processing functions: detection of dew condensation amount deterioration and high temperature/high temperature deterioration detection, it is possible to sufficiently detect deterioration of the humidity sensor with only one of the processes.

The CPU 5 has a function of outputting and displaying a sensor error signal on the display unit 8 when the cumulative value exceeds a predetermined value in any of dew condensation amount deterioration detection, high temperature, and high temperature deterioration detection.

The dew condensation time tQ (min (minutes)) exceeds 4 m1n,
As you get older, your stress will increase accordingly.
A table showing the relationship between the dew condensation time tQ and the stress amount α8 as shown in FIG. 3 is stored in the memory unit 7. In this table, K<Klku...<Kll, and α8I<α8°<...<αB+.

In addition, in a high temperature state (for example, 90% RH or higher), the stress increases as the high temperature state continues, so a table showing the relationship between the element temperature information TX ('C) and the stress amount α1 as shown in Fig. 4 is prepared. It is stored in the memory section 7. In this table, temperature T1<Tz<・"<T(n-1
)<Tn, and accordingly the stress amount α is α, , <αA
t<...<αA7.

Next, with reference to the flowcharts shown in FIGS. 2(a) and 2(b), the deterioration detection processing operation of the humidity measuring device of the above embodiment will be described.

<High temperature/high temperature deterioration detection> The deterioration detection processing execution cycle is tp = 1 min, and 1
Every min, the judgment of "°processing timing or pa" in step ST (hereinafter abbreviated as ST) becomes YES, and then it is judged whether the measured humidity H, is 95%RH or more (Sr2).When the humidity HX is 95%RH If it is not above, the judgment will be No and Sr
Move to 1. If the humidity HX is 95%RH or higher, 5T2
(7) Determination YESt'5T13. The process from 5T13 onwards is a process for detecting the deterioration of the N amount, which will be described later.

At Sr1, it is determined whether the flag Fp-0, that is, whether the dew condensation amount deterioration detection process has ended or not.Since the initial Fp=0, the determination is No, and the process moves to Sr1, where the high temperature and high humidity deterioration detection process begins. . First, the humidity H6 measured with Sr1 is 90
%RH or more is determined. Humidity HX is 90%R
If it is not higher than H, it is assumed here that the temperature is not high, and standard life stress setting is performed. That is, the value α is stored as α (Sr1). Next, this α is stored as the stress amount α during the current tP.

and store it (Sr1). Further, the stress cumulative value RI stored in the memory unit 7 is successively stored, and is set as the stress cumulative value ΣS (n-1) up to the previous time (Sr8).

Next, the current stress amount α is added to the stress cumulative value ΣS (n-1) up to the previous time. is added to calculate the cumulative stress value ΣS (n) up to this time (Sr1). Then, this stress cumulative value ΣS (n) is stored in the memory unit 7 as data D (STIO), while this stress cumulative value ΣS (n) up to this time is compared with the deterioration judgment reference amount ΣS MAX, and ΣS MAX Determine whether ≦ΣS (n) (
STII), ΣS (n) has not reached ΣS )IAX, the current process ends with a determination No of 5TII. Then, when the next l min arrives, S
Executes processing after TI. Now let αc=1 and ΣSM
If you set AX = 35040Hr and continue to measure humidity for 4 years with humidity HX below 9o%RH, ΣS (
n) becomes 35040Hr, and the judgment of 5TII is YES.
Then, sensor error processing is executed, and L on the display section 8 is displayed.
ED is lit. This notifies that the humidity detection element has deteriorated (ST12).

Since the deterioration of the humidity detection element is determined after 4 years of continuous measurement when humidity HX is less than 90% RH, the earliest possible time is if measurement is continued when humidity H is 90% RH or higher. Deterioration is determined. In other words, if the determination of "H≧90%RH" is YES in Sr1, the temperature is high;
In this case, from the measured temperature TX, the stress amount α,
Calculate. For example, if the temperature T is T2<TX<T3, the stress amount αA3 is read out from the memory unit 7 with reference to the table in FIG.
is the current stress amount α. (Sr1), and the current stress amount α is added to the previous stress amount integrated value ΣS (n-1). (αA3) to calculate the cumulative stress value ΣS (n) up to this time (Sr8.5T9)
. The stress amount αA3 is the standard stress amount α. It is set several times larger than that, and therefore α between 1p. However, if αA3 is accumulated every 1p, ΣS□8 will be reached much earlier than 4 years, and a sensor error will be displayed earlier. It turns out. The measured temperature T is T a < T X < T
5, the accumulated stress amount is αA5 and 1,
α. 〈α, , so the cumulative value ΣS (n) is ΣS□
It will reach 8 even faster. In this way, in this example, the higher the temperature continues, the more
A large amount of deterioration is output, and the timing at which it is determined that the humidity detection element has deteriorated is made earlier.

<Detection of deterioration in amount of dew condensation> If the measured humidity HX is 95% RH or more, it is determined here that there is dew condensation. Dew condensation is determined by:
The measured humidity HX may be set to an appropriate value between 95% and 100% RH, but the reason why it is set to 95% is that the measurement accuracy at an ambient temperature of 25°C is ±5% RH, and the difference of 5% RH is This is because when compared in terms of temperature, this corresponds to a variation of about 0.5°C, and this value can be judged to be sufficiently small considering the stability of the control environment.

If the judgment of “IHX≧95%RH in Sr1” is YES, it means that condensation has occurred, and the process moves to 5713.
It is determined whether flag F=1, that is, whether dew condensation amount deterioration detection processing is in progress. At the beginning when the condensation state is reached, this judgment is NO, and the condensation retention time t9 should be reset at 5T14.
), flag F9 is set to "1", and dew condensation amount deterioration is started (ST15).Then, the dew condensation retention time tQ up to that point is
(N-11 is also added to calculate the dew condensation retention time tq (r+1) up to this time (ST16).Next, it is determined whether the dew condensation retention time LQ+I11 is 4 min or more 5T17), +07. If it is not 4 min, the judgment is No and the stress due to dew condensation is not taken into account and the process moves to Sr1.If 5TI7 is t,,,,)≧4 min,
The LED segment for displaying the dew condensation alarm on the display section 8 is turned on to notify that the humidity detection element is in a dew condensation state (ST1B), and the process moves to Sr1. Measured humidity HX is 95%R
If the Sr
2. Repeat the processes of 5T13, . . . , 5T1B, . . . and continue measuring the dew condensation retention time t□0). During this time, the stress amount due to the deterioration of the amount of dew condensation is not integrated.

Eventually, when the measured humidity H8 becomes smaller than 95%RH,
In other words, when the dew condensation state is interrupted, the determination of Sr2 becomes No, and the process moves to Sr1. In Sr1, flag Fp is 1″ until then
Therefore, the determination of ``Is the dew condensation amount deterioration detection processing completed?'' is YES, and here, the flag Fp is set to ``0'' and set to 5T.
19), condensation retention time j Q (11-11> 4 m
5T20), LQTn-1+ is 4
If it is less than min, ignore this dew condensation and Sr1
fly to

If the dew condensation retention time jQ(n-11 exceeds 4 m1n in Sr20, it is assumed that there is stress due to the dew condensation amount, and the dew condensation retention time 1. Read out the stress amount α8 corresponding to Sr21), and add this stress amount α8 to the stress amount α. Close it and memorize it. Stress amount α shown in Figure 3
. , αB2, . . . αB0 are large values on the order of Hr (time).

For example, if the condensation retention time t9 is 4 or more and less than 3,
Stress αB4 is α. It is stored together (Sr22).

Then, the process moves to Sr8, and the cumulative stress amount up to that point is read out from the memory unit 7 and stored as the cumulative stress amount ΣS (n-1) up to that point, and this stress amount ΣS (n-1) is , stress amount α. (α+14) to calculate the current cumulative stress amount ΣS (n).
T9), this ΣS (n) is stored in the memory unit 7 (STIO), and the deterioration judgment reference amount ΣS MAX and the stress integrated value ΣS (n
), and if ΣS08 is not ΣS (n), then 1
．． The process waits until the next processing timing arrives after the elapsed time, but if ΣSMAX <ΣS (n), the sensor error LED on the display unit 8 should be lit and the time has come to consider that the humidity detection element has deteriorated. inform about something.

As the dew condensation time increases (t, ll +, Kz, K3, etc.), the amount of stress increases extremely, so the accumulation of deterioration is greatly accelerated, and the time is much earlier than the standard life of 4 years. has reached the end of its lifespan, and this can be accurately notified.

In the above embodiment, in order to obtain the amount of stress corresponding to the measured temperature in a high temperature state, the relationship between temperature and stress amount is created in a table and stored in the memory, but instead of this, the relationship between temperature and stress is The approximate equation shown may be stored and the measured temperature may be applied to this approximate equation to calculate the stress amount.

In addition, in the above example, when the measured humidity is 90% 2 RH or more, the temperature is considered high temperature, and the amount of accumulated stress is changed according to the temperature in the high temperature state, but the humidity is also divided into several stages, and the combination of humidity and temperature is changed. The amount of stress may be changed accordingly.

In addition, in the above embodiment, the amount of stress is weighted and added in the case of high temperature and high humidity, but the amount of stress is weighted and added when the temperature is high or humidity is high. You can do it like this.

(f) Effects of the Invention According to this invention, the cumulative value of the duration of the high temperature state is calculated from the humidity and temperature measured using the humidity detection element and the temperature detection element, and deterioration is determined from this cumulative value. Because of this, deterioration can be grasped quantitatively, and the deterioration of the humidity detection element can be notified by oneself without the use of a special instrument, and the humidity detection element can be replaced as early as possible. Therefore, it is possible to always measure humidity with a small measurement error.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the hardware configuration of a humidity measuring device in which the present invention is implemented, and FIGS. 2(a) and 2(b) are for explaining the deterioration detection processing operation of the humidity measuring device. 3 is a table diagram showing the correspondence between dew condensation time and stress amount stored in the memory section of the humidity measuring device, and FIG. 4 is a table diagram showing the correspondence between the dew condensation time and stress amount stored in the memory section of the humidity measuring device. FIG. 3 is a table diagram showing the correspondence between temperature information and stress amount. 1: Humidity detection element, 3: Temperature detection element, 5: CPU,
6: Timer, 7: Memory section, 8: Display section.

Claims (1)

[Claims] (1) A humidity detection element, a temperature detection element, a means for measuring humidity and temperature based on the output of the element, a means for determining whether the measured humidity exceeds a predetermined value, and a means for determining whether the measured humidity exceeds a predetermined value. It is characterized by comprising means for determining whether or not the humidity and/or temperature exceeds a predetermined value, an accumulation means for accumulating the time during which the humidity and/or temperature exceeds a predetermined value, and means for outputting the cumulative value of the accumulation means as an amount of deterioration. Humidity measuring device.