JPS58135445A - Humidity detector - Google Patents

Abstract

PURPOSE:To perform automatic heat cleaning in addition to the periodical cleaning, by dividing previously the moisture of an expected range into plural stages, delivering successively the voltages corresponding to the divided stages to compare them with the voltage delivered from a moisture-sensitive element and then detecting a fault if any. CONSTITUTION:The resistance value, i.e., the output voltage value of a moisture- sensitive element 12 has a logarithmic change to the change of humidity. Therefore, a logarithm-proportion converting circuit 13 is provided at the next stage of the element 12, and the output of the circuit 13 is fed to a comparator 14. On the other hand, the analog reference voltage representing each stage of the relative humidity and varying in steps is fed to the comparator 14 from a reference voltage generating circuit 18 and compared with the input voltage showing the instantaneous value of relative humidity given from the circuit 13. When a microcomputer 15 decides a fault from the result of comparison, a fault signal is transmitted to a relay controlling circuit 17. Then the electric power is supplied to a resistance heat generator 5 during an expected time, and the element 12 undergoes the heat cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention (1) relates to an electrical resistance type humidity detection device;
6'' relating to a humidity detection device having a mechanism for heating and cleaning a sensor A1 element.

Temperature sensing elements that have been constructed and put into practical use include a metal oxide 4#P4 whose electrical resistance changes sensitively to changes in humidity.

FIG. 1 is a sectional view showing an example of a metal oxide moisture sensitive element and a resistance heating element. In the figure, 1 is an alumina substrate, 2 is a moisture sensitive material, 3 is a lower electrode, 4 is an upper electrode, and 5 is a resistance heating element. Incidentally, the above-mentioned elements 1 to 4 form a moisture sensing element 12.

This moisture sensing element 12 is manufactured by the following method.

That is, the lower electrode 3, which is a conductor, is placed on the alumina substrate l.
．． Moisture sensitive material 2. The upper electrodes 4 can be created by sequentially printing and firing them using a screen printing method.

The moisture-sensitive material 2 is a moisture-sensitive material paste made of F@A1104 prepared by mixing, calcining, and pulverizing, high melting point crystallized glass, and an organic vehicle, for example, by a well-known method. 40μm by screen printing method
It can be produced by forming a film with a thickness of

Further, the resistance heating element 6 is provided on the back surface of the alumina substrate l.
Similar to the temperature sensing element 12, it can be created by printing and firing using a screen printing method.

As is well known, the temperature-sensitive element 12 created as described above is caused by a change in resistance value between the lower electrode 3 and the upper electrode 4, that is, a change in resistance value of the moisture-sensitive material 2. Detect changes in

As is well known, such a moisture sensitive element must be heated and cleaned and constantly refreshed to ensure its integrity and reliability. 1st! The resistance heating element 5 of GL is for this purpose. That is, the thermal cleaning of the element 12 is performed by supplying a current to the heating element 5 for a period of time.

As is well known, metal oxide temperature sensing elements are
Adsorption and desorption of moisture is performed in accordance with the relative a1 degree of the atmosphere.

That is, deep tL using the temperature sensing element 12 as described above.
The detection device can detect the relative humidity of the atmosphere depending on the Sa#ε of the 11th century, and the temperature-sensitive material 2.
This is because the resistance value of

On the other hand, in the humidity sensing element 12, even if the humidity is constant, the resistance value increases little by little.

This is because the moisture adsorbed in the initial stage becomes hydroxyl and generates hydroxide on the surface of the moisture sensitive material 2. This phenomenon progresses over a long period of time compared to the aforementioned phenomenon of adsorption and desorption depending on the ambient temperature.

In the above-mentioned simple adsorption of moisture, the moisture is easily adsorbed and desorbed when the relative temperature changes, but when hydroxide is generated, the desorption of the hydroxide is difficult at room temperature. However, heating at a temperature of 400°C or higher is necessary. Therefore, in order to remove this hydroxide and refresh the temperature sensing element 12 so as not to cause lll11 in temperature detection,
Heated cleaning is il! becomes.

Further, although it depends on the atmosphere in which the humidity element 12 is placed, unexpected foreign matter may adhere to the temperature sensing element 12. Typical examples include droplets from tempura oil, hairspray, etc., highly concentrated cigarette smoke, and other dust. J4 like this
Even when moisture adheres to the surface of the humidity sensing element 12, a difference in the degree of detection -ζ- occurs.

Therefore, in this case as well, yr4@
w. It is necessary to heat and clean the moisture sensitive element 12 and refresh it. In such a case, by performing heating cleaning, normal fi& can be detected again.

By the way, although it depends on how the a* detection device is used, in a mode where there is a membership fee to keep the sensor 12 in constant operation,
Frequent thermal cleaning is not preferred.

This is because, in the above embodiment, in the case of a heating cleaning method, humidity cannot be detected not only during cleaning but also after cleaning until the IIA concentration element is cooled down to ms.

Examples of such usage ms include usage in which 011tL is constantly detected and m degrees are always controlled to a single level, and a circuit that converts an electrical signal (for example, voltage value change) from a moisture sensing element into concentration. One possible use is to provide a digital display section.

However, considering the wide range of performance, accuracy, reliability, and lifespan, as well as the ability to remove contamination attached to the element, there are currently However, there is no material that can be put to practical use. So C,
Conventionally, the composition of the moisture-sensitive material 2 and process conditions such as pulverization and firing have been devised so that the reliability of the moisture-sensitive cord 12 can be ensured even if the S degree of thermal cleaning is reduced.

However, at present the effect is small.

Therefore, in a humidity sensing element used in a mode that constantly detects and displays humidity, it is necessary to minimize the frequency of heating cleaning.

Figure 2 shows a metal oxide moisture sensitive element at 24°C and 50sR.
Installed in a constant rJIif tank of H (N vs. a1 degree), and measuring the species change detection IK difference from the change in resistance value of the element over time, the 01 degree ejection wA difference (chiR) f) - progress time (h
) 4e sex diagram.

(b) As is clear from the figure, when the elapsed time (h) is less than 24 hours, the detected humidity difference is less than 2@nHm.

Therefore, conventionally, in the case of tags used for general residential use, general heating cleaning is usually performed at most 1 day at most.
This is because in a normal atmosphere, by refreshing once every 24 hours,
This is because the reliability of the moisture-sensitive cord 12 can be ensured over a long period of time.

In other words, it can be said that IZIi degrees per day is sufficient for heating cleaning mainly aimed at removing hydrochloride formed on moisture sensitive materials.

However, if the moisture-sensitive cord 12 becomes contaminated due to the unexpected adhesion of foreign matter as described above (hereinafter referred to as an abnormal situation), as described above, a cleaning system that performs cleaning at a certain period of time (once a day) is required. So, from the time it gets contaminated, until it's cleaned and refreshed, it's the correct ALFL
There was a point at which it became impossible to detect L.

This is because, for example, if the moisture-sensitive material 2 is contaminated with the above-mentioned multiplicative tempura oil, the resistance value of the moisture-sensitive material 2 will increase more than 10 times, and in the case of hot cigarettes with a high temperature of 2.5 This is because the resistance value increases twice as much.

Therefore, in the 6S wet Hayabusa, which is used in a manner that constantly detects and displays the temperature, it has been conventionally
As mentioned above, for example, if 6C cleaning is performed on a daily basis, there is a need for an FFI degree detection device that can accurately detect abnormalities and perform heating and cooling separately. .

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to reliably detect an abnormality with high reliability, and to perform heating cleaning in addition to periodic cleaning. The tIIIWL detection setting is performed automatically in the detection kaiseki.

In order to achieve the above object, the present invention includes: a means for applying a voltage to a humidity sensing element; a voltage output means for dividing a certain range of dllll into a plurality of stages in advance and sequentially outputting voltages corresponding to the stages; The voltage output from the voltage output means and #
A comparator that generates an output signal when the polarity of the difference between the voltage and the voltage output from the SS element is reversed, and a voltage output Iv corresponding to the output signal from the comparator.
ζ7 is provided with means for capturing and storing the voltage value of 111i1.

Further, in the present invention, in order to achieve the above-mentioned object, #6 means for calculating the average value (-th order average It) of the previous scheduled number of voltage values stored in the grasping storage means; The value is further determined as necessary (a means for collecting a certain planned number of items to obtain a quadratic average value, and a means for obtaining a secondary average value, which is obtained at a time later than that of the -second average value). Similarly, the first-order average value or the second-order average value obtained later than the #IJ-order average value are compared, and the one with the above-mentioned −order average value and the second-order average value than the −order average value are compared. If the position of the primary average value obtained with a delay in time !j or the secondary average value obtained with a time delay than the above-mentioned -order average fil exceeds a certain permissible range, A means for outputting a signal for heating the humidity sensing element, and a means for heating the humidity sensing element using the signal from the heating signal outputting means are provided.

Hereinafter, the present invention will be explained using the drawings.

Figure '143 is a C circuit diagram showing an embodiment of the allf lateral extraction device of the present invention.

In the same figure, 10 is a 50H1, IV power input terminal,
11 (i amplifier, 12 is a moisture sensing element, 13 is a logarithmic-proportional variable circuit, 13m is an inversion 1 width 1.14 is a comparator, 1
5 is a microcomputer, 16 is a heating element relay, 17 is a relay control path, 17a is a timer, 17b is a switch, and 1B is a reference voltage generation circuit. Note that 5 indicates a resistance heating element as in FIG.

The operation shown in FIG. 3 will be explained below.

As is well known, the resistance value of the sensor 11133 element 12, that is, its output voltage value changes logarithmically with respect to a change in f1 degree. Therefore, in this third example, a logarithmic-proportional conversion circuit 13 for converting the logarithmic change in the output voltage value into a proportional change is provided at the next stage of the humidity sensing element 12.

Therefore, the output voltage of the logarithmic-proportional conversion circuit 13 is
As shown in Fig. 1m), it is proportional to the instantaneous value of relative am.

As described above, the output voltage of the logarithmic-proportional conversion circuit 13, which calculates the instantaneous value of relative humidity, is input to the inverting input terminal of the comparator 14.

On the other hand, the microcomputer 15 divides, for example, 10qbRH to 9011RH, which can be considered as the general household environmental humidity, into 64 stages l1l (therefore, one stage is 1.2!i*RH), and outputs each stage. Predetermined digital reference voltage signals are sequentially outputted at the latest in one cycle to generate a reference voltage vm*x.
s is supplied.

Therefore, from the reference voltage generation circuit 18, as shown in FIG.
An analog reference voltage representing each stage of relative humidity and changing stepwise is generated at the same period, as shown in 1.
It is supplied to the non-inverting input terminal of the comparator 14.

The comparator 14 compares an input voltage that detects the instantaneous value of relative humidity with an analog reference voltage that changes in 64 steps. Then, the output signal of the comparator 14 is inverted and becomes a @1'' level signal when the m-th analog reference voltage becomes higher than the input voltage that causes the relative [* instantaneous -].

On the other hand, microcontroller 1511. When the output signal of the comparator 14 reaches the level ''1212, the digital reference voltage signal that was being output from itself is changed to the temporary humidity 1 (i
(14, is 1, , 2... any integer of song 64,
Also, i is a natural number).

In addition, the microcomputer 15 calculates the -order average humidity Xj( j
−s−α+β).

Furthermore, the microcomputer 15 calculates the −th order average temperature Xj−β
+1 secondary average humidity 11YjCI exposure 1-1 (su2)
seek.

Therefore, if we now assume that an abnormality occurs in the humidity sensing element 12 during the instantaneous fl11 degree adjustment of the AIRI, and the measured value suddenly increases as shown in (1) in Fig. 7, then the -th average temperature Xj is α including the A-th time, as shown in (2) in the same figure.
Over the #1 stationary period of the batch, - i.e., XA-α
Increases stepwise from +1 to 4.

Accordingly, as shown in (3) in the same figure, the secondary average humidity Y1 is calculated by (α+β) times of # from the time of change of the instantaneous humidity Hi.
- i.e., increases at a lower rate than YA-aj over the period.

Next, in the microcomputer 15, the deviation of the −th order average m*! is determined, and the deviation is compared with the set value δ.

When the degree deviation is larger than the set value δ, it is determined that an abnormality has occurred, and the microcomputer 15 transmits an abnormality signal to the relay control circuit 17, turns on the switch 17b, and controls the resistance heating element for a scheduled time. 5. As a result, the sensitizer 12 is heated and cleaned.

Note that by appropriately selecting α, β, and a, it is possible to determine how many seconds the abnormality must continue before it is determined that an abnormality has occurred, and how many seconds after the occurrence of the abnormality it is determined that the abnormality has occurred.

When the scheduled time has expired and the contacts of the heating element relay 16 are opened, the heating of the humidity sensing element 12 stops. After the completion of heating, the above-mentioned humidity-electrical operation by the microcomputer 15 is prohibited during the scheduled time until the temperature of the sensitizer 12 returns to room temperature.

In the above explanation (explanation of the first embodiment), within the microcomputer 15, the negative-order average m This was a case in which the presence or absence of an abnormality was determined by this.

However, two temporally different linear averages full al
l Xj - For example, it is clear that the presence or absence of an abnormality can be determined by comparing the deviation of a certain order average temperature XJ and the first order average humidity Xj-1-d after α times with the set value r. It is.

Hereinafter, an example of the operation of the microcomputer 15 will be mainly described.
Taking the embodiment of Il as an example, it will be explained with reference to the flowchart of FIG. 5 and the explanatory diagram of FIG. 6. Note that, for convenience of explanation, in this case, both α and β in the above explanation were set to 20.

First, in step 81 in FIG. 5, the count value i of the instantaneous temperature measurement counter (hereinafter referred to as 1 counter) and the count value j of the primary average humidity calculation counter (hereinafter referred to as j counter) are reset, and the respective counts are reset. Set to 0.

In step S2, the count value i of the i counter is set to 1.
Add. In step S3, a time slot counter for one second, which is the time for one measurement of instantaneous humidity, is reset. number j in step s4.

The reference voltage signal V corresponding to the 64th stage of relative a degree is set to the initial value v0.

In step S5, the output signal of the comparator 14 is @
It is determined whether or not it has been inverted to the l'' level.

If it has not been inverted to the "l" level, the process advances to step s6. 11 in step 86, the reference voltage signal V at this time is
Apply a voltage ΔV corresponding to relative [tl stage up.

This procedure--steps s5 and s6 are repeated until it is determined that the output signal power of the comparator 14 is inverted to the s@1# level at step Ss.

If it is determined in step s5 that the output of the comparator 14 has been inverted to the l'' level, the process advances to step S5.

In step S7, the output signal of the comparator 14 is @
The value of the reference voltage signal V when it is inverted to l level is taken as the instantaneous humidity (hereinafter referred to as data) H, at that time,
Store in memory.

In step S8, the counter value i of the t counter is
20 (generally α) - that is, it is determined whether the instantaneous humidity measurement exceeds 20@. If the above relationship does not exist, the process proceeds to step 89.

In step 89, it is determined whether the count value 1 is in the relationship of 1 wealth 20 or not. If the above relationship does not exist, the process advances to step 81G. In step 81G, it is determined whether one second (this time can be arbitrarily set) has elapsed since the time slot counter was reset in step 83. If it has not elapsed, the process waits until it elapses, or returns to step S2 when it elapses. ``The above-described cycle continues until the count value 1 of the instantaneous temperature constant counter increases to 20.

If the count value l is determined to be 20 in step S9, the process advances to step 811. In step 811, step S
The average [Xt of the 20 pieces of data H1 to Hgo stored in the memory in step 7 is calculated, and the X in parentheses is stored in the memory. After this step 811 is completed, step 810
Return to

In step 810, as described above, it is determined whether one second has elapsed since the time slot counter was incremented, and li! If it has passed, the process returns to step S2. The count value amount at this time is 21, as is clear from FIG.

At this time, thread < step S3 → step S4 → step S
5→Step S6, the 21st data horse is obtained. In step S7, this data)
Its is captured and stored in memory. Step S8
Then, it is determined that the relationship of Tortoise>20 is satisfied. Therefore, the process advances to step 812.

- In step 812, the first data H1 is subtracted from the average value X1 of the first 20 data H1 to H211 obtained in step 811, and the first data H1 is subtracted from the average value X1 of the first 20 data H1 to H211 obtained in step 811. By dividing the value obtained by adding the 21st data H□ by 20, the updated 20
My data H! , H1...H□ average values x and f are determined.

Thereafter, the process proceeds to step 81B, where the count value JK1f of the j counter is added (see FIG. 6).

Furthermore, in step S12, the average value X1-ts of the 20 data obtained here is stored in the memory -ζ
Store.

In step 814, the count value j of the j counter becomes j
>Whether or not there is a 19 relationship! 41 Disconnect 6° If the above relationship does not exist, proceed to step 8111.

In step 815, it is determined whether or not the count value j has a relationship of j-19. If the above relationship does not exist, the process returns to step 82 after the determination in step 81G.

The cycle C1,j as described above is repeated until it reaches 19. If the count value j is determined to be 19 in step S16, the process advances to step 8111.

Step 816 CM, the average value Y of the primary average temperature aX stored in the memory in step 811 and the primary average temperature direct X, - of the 19 items stored in the memory in step S12.
Find 1. Note that in this step 816, the secondary average temperature [Y, is stored in the memory.

When this step 816 is finished, the process returns to step s2 after passing through the judgment in step 810 again. At this time, the count value J becomes 40 as shown in FIG. 6 b.

Then, step 83 → step s4 → step 85 →
The process proceeds to step 814 via step S6→step s7→step 88→step S12→step 813.

Note that the count value j at this time is 11, which is clear from FIG.
Proceed to.

In step 1917, it is determined whether the negative average density Xj-II is within the range Iζ of the secondary average density YJ-II±-. If it is not within the range, it is assumed that an abnormality has occurred, and the relay control 1 is activated to heat and clean the humidity sensing element 12.
A signal is output to turn on switch 17b of path 17.

That is, in the diagram 1lIs, the process advances to step 81g for performing heating cleaning. Step 818 16JI
When Il is completed, the process advances to step 819.

In step 81G, a delay timer is started.

In the subsequent step 82G, a value is set for the delay time set by the delay timer, that is, as described above,
After the heating cleaning is completed, it is determined whether or not the delay timer has counted up based on the count value that is maintained until the humidity sensing element 12 is cooled to room temperature.

If it is determined that the slow grinding timer has counted up to the count value, the process returns to step 81.

At this time, in step Sl, the first processing described above is performed - that is, the count value 1 of the 1 counter and the count value j of the j counter are reset to 0, respectively.

On the other hand, if it is determined in step 817 that it is within the range described above, the process proceeds to step 821.

In step 821, it is determined whether or not the count value j has a relational polynomial ζ of j>39. If the relationship is not established, the process proceeds to step 822.

In step 822, the calculation shown in equation (1) is performed to obtain Yt, . Moreover, in this step 822, this determined average value is stored in the YJ-184 memory.

When this step 822 is completed, the process returns to step s2 via the judgment wfr of step 810 again. This cycle continues until the count value of the j counter reaches 40. When j reaches 40, it is determined that the condition of step 821 is satisfied, so the process proceeds to step 823.

In step 823, the same calculation as in step 812 as shown in equation (2) is performed, and the average allEYj-+a after the secondary average humidity Y0 is determined. Moreover, in this step 823, the obtained average fi11 degrees Yj-ts + is stored in the memory.

Yj-1a-Yj-go-Yj-ms"Yj-so
--・Song...o121 When this step 823 is finished,
After making the determination in step 81G again, the process returns to step s2.

That is, the microcomputer 15 activates the moisture sensing element 12 only when the condition of step 817 is not satisfied and it is determined that an abnormality has occurred.
Outputs a - signal for heating and cleaning.

However, other than that, step 82 → step S3 → step S4 → step sI → step s6 → step 8
7→Step S8→Step 812→Step 813→
Step 814 → Step ″7'817 → Step 821
→The cycle of step 828 is continued.

The above explanation was based on the arithmetic processing method according to the flowchart shown in FIG. 5, but the arithmetic processing method according to the flowchart shown in FIG.
It works with Jin, who determines whether there is an abnormality.

Note that in FIG. 8, steps indicated by the same reference numerals as in the ms diagram perform the same processing and judgment as in FIG. 5.

The above was an explanation of an example of the operation of the microcomputer 15.
This can be summarized as follows.

In other words, as mentioned above, during normal times, there is a fee for cleaning the city Jakajima, but in this embodiment, in order to determine whether or not it is an abnormal time, the resistance value of the sensitive alIIA child 12 suddenly increases. If the phenomenon of increase and decrease continues for a certain period of time or longer (C), it is determined that an abnormality has occurred, and the humidity sensitive element 12 is heated and cleaned only in this case.

In this way, when an abnormality continues for a certain period of time -ζ, it is determined that an abnormality has occurred.Even in a steady state other than an abnormality (II), the resistance value temporarily increases or decreases suddenly, just like in an abnormality. This is because there may be cases where this is the case.

This sudden change in resistance value is caused by, for example, the temperature of hot water and ta.
Temporarily close windows and doors in rooms where Il is controlled
This is a case where the ctllJ is released and the a-le condition is significantly shaken. However, in such a case 6ζ
Of course, there is no membership fee for heat cleaning.

Note that heating cleaning of the humidity sensing element 12 in a steady state is performed using, for example, the relay control circuit 17 as shown in FIG.
This can be done by setting the timer 17 (eg, to operate once every 24 hours).

Next, the humidity sensing element 12 is ll! How the humidity detection device of this embodiment works in a different way will be explained with the humidity detection device being contaminated at the same time.

(1) When cooking oil adheres to the sensitizer 12 and contaminates it.

First, check the indoor relative humidity at 55 SRH and maintain this relative humidity. In this state, before applying cooking oil, the resistance value of the moisture sensing element 12 is determined as #j, 165
It was Ω. Next, when the resistance value was measured while applying the oil, it rapidly increased to fi3E, 4MΩ.

However, in the a1 degree detection device of this embodiment, the aJ, 4
When the abnormal value of MΩ continued for approximately 20 seconds, a power of 1.8 W was applied to the resistance heating element 5. The application time was 10 minutes, and the A1 sensitive element 12 was heated at 550°C.

As a result, the adhering oil was almost completely removed, and after 20 minutes, for example, after energization, the resistance had returned to 165Ω, which is the contaminated resistance value.

(2) Breathe into the temperature sensing element 12 When sprayed for 3 seconds.

Similarly to (1), 1ll at the indoor relative temperature f55*RH.
I411 and maintain this relative humidity. In this state, the resistance value of the fi-sensitive toxin 12, which is separate from ill, was measured and found to be 160Ω.

Next, while blowing exhaled air onto this element 12 for 3 seconds,
When the resistance value was set to #11, it drastically decreased to 13Ω. However, the resistance value of the 7 second test is 16
It returned to Ω to 0. During this time, the high VL detection device 1 of this embodiment
1. No heating IJ-Jung operation, normal state 1
It held 1A.

More mf! As is clear from the above, the present invention has the advantage of not only being able to reliably detect abnormal conditions with high reliability, but also being able to automatically perform heating cleaning in addition to periodic cleaning during normal conditions. be.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a temperature sensing element and a resistance heating element, and Fig. 2 is a humidity detection w! 411-A characteristic diagram showing an example of elapsed time characteristics, FIG. 3 is a circuit diagram showing an embodiment of the a1 degree detection device of the present invention, and FIGS. FIG. 5 is a flowchart for explaining an example of the operation of the microcomputer 15 in FIG. Figure 7 shows the data H1 and the negative average humidity Xj. Figure 8 shows the relationship between the secondary average humidity wLYj
This figure is a flowchart for explaining another example of the operation of the microcomputer 15 in FIG. 3. 5... Resistance heating element, 11... Amplifier, 12... AlI element, 13... Logarithm-proportional conversion circuit, 14...
・Comparator, 1s...Microcomputer, 16...Heating element relay, 17...Relay control circuit, 17b...
Switch, 18...Reference voltage generation circuit representative layer person, lawyer Michito Hiraki 21 Figure 22 Figure 1 Elapsed time (h)

Claims (2)

[Claims] (1) In a humidity detection device having a heating cleaning machine 411I for a wire mesh oxide moisture sensitive element that detects a change in humidity f based on a change in resistance m, a voltage is supplied from a power source 71 to detect the type of atmosphere. The humidity sensing element changes its resistance value - that is, the output voltage value, in accordance with the change; the voltage output means divides the humidity in a predetermined range into a plurality of levels in advance and sequentially outputs voltages corresponding to the humidity levels; a comparator that generates an output No. 16 when the polarity of the difference between the voltage output from the voltage output means and the voltage output from the humidity sensing element is reversed; Calculate the average value of the previous scheduled number of voltages 11 delivered in the means for storing the voltage values (or 11 representing this) of the voltage output means and the voltage 11 stored in the means for storing voltages in the III period. Compare the means and the two average values obtained at different times, and use the older average value as a reference lζ, and if the newer average value increases or decreases by more than a certain tolerance range. A humidity detection device comprising: means for outputting a signal for heating the humidity sensing element; and means for heating the humidity sensing element based on a signal IC from the heating signal output means. . (2) In a humidity detection device that has a heating cleaning mechanism for a wire-mesh oxide humidity sensing element that detects humidity changes based on changes in resistance value, when voltage is supplied from a power source, its resistance changes according to changes in atmospheric humidity. value - That is, the humidity sensing element that changes the output voltage value, the voltage output means that divides the humidity in the predetermined range into 41# steps in advance and sequentially outputs the corresponding voltages, and the voltage that is output from the voltage output means. Voltage and 1! II. A comparator that generates an output signal when the polarity of the difference between the voltage output from the moisture sensitive element is reversed, and a comparator that generates an output signal according to the output signal from the comparator,
means for loading and storing the voltage value (or a representative value thereof) of the voltage outputting means; and means for calculating a linear average value of the previous scheduled number of voltage values stored in the loading and storing means. , a means for obtaining a quadratic average value by further collecting a predetermined number of said -dimensional average values, and a means for obtaining a quadratic average value by further collecting said -dimensional average values and a quadratic average value obtained temporally later than said -dimensional average values. When the secondary average value increases or decreases from a certain punch capacity range with respect to the negative average value as a reference, , a means for heating the temperature sensing element by a signal from the heating signal output means.
1e detection device.