JPS6142016A - Dew condensation preventing device - Google Patents

Abstract

PURPOSE:To output an attention signal to the external to prevent the occurrence of dew condensation by detecting the surface temperature of a material as the dew condensation prevention object and comparing this temperature with the wet-bulb temperature of the atmosphere in a room at this time and obtaining the differential value of the temperature difference and comparing this value with a preliminarily set reference value. CONSTITUTION:The wet-bulb temperature of the atmosphere in the room is inputted to one input terminals of comparing circuits 25a and 25b, and surface temperature on plural positions of a sample object are inputted to the other input terminals of comparators 25a and 25b. Comparators 25a and 25b compare a surface temperature Tsi of the object with a wet-bulb temperature TH of the atmosphere in the room at this time, and output signals are obtained in case of Tsi<TH and are inputted to an OR circuit 26. If any of output signals of plural comparators is turned on, a signal is sent to the external by a relay driving circuit 27. A differential value comparator 32 compares a differential value DELTATDi of a temperature difference DELTAT between the wet-bulb temperature TH in the room and the surface temperature Tsi of the object with a preliminarily set reference value C from a reference value generator 30, and a turn- on output signal is sent to the OR circuit 26 in case of DELTATDi>C. If any of output signals from comparators 25a and 25b and the differential value comparator 32 is turned on, a signal is sent to the external.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method that prevents dew condensation on a specimen during a humidity and temperature cycle test, and a dew condensation method that is effective in preventing dew condensation on equipment stored indoors. Concerning preventive devices.

[Prior art]

Conventionally, methods for preventing dew condensation on specimens have been determined empirically by humans based on the temperature and humidity of the indoor atmosphere, the rate of change in temperature and humidity, the heat capacity of objects, and other factors. Additionally, a separate hygrometer was installed near the object, and this was used to determine the presence or absence of a condensation storm.

However, according to the above-mentioned conventional method, since judgments were made empirically by humans, there were no specific indicators to serve as a standard, and the judgments varied greatly from person to person, making it impossible to prevent condensation accurately and completely. Furthermore, in the case of the method of setting hygrometers, there are restrictions on the locations where the hygrometers can be installed, so it is not possible to install a large number of hygrometers, and it is also expensive.

[Problem that the invention seeks to solve]

Recently, temperature and humidity cycle tests of expensive specimens such as plant control computers have been increasing, but the temperature and humidity in this test is generally measured using a single ρ temperature and humidity detector installed near the air outlet of a constant temperature room. is controlled by the value of

For this reason, due to a delay in tracking the surface temperature of the specimen due to the rate of change in ambient temperature and humidity and the heat capacity of the specimen, a temperature difference occurs between the ambient temperature (control temperature) and the object surface temperature, and the surface temperature of the specimen In this case, there is a possibility of an increase in humidity or the occurrence of dew condensation, which may cause damage to the specimen or deterioration of performance, and it is required to prevent this.

The present invention was made in response to such demands, and an object of the present invention is to provide a dew condensation prevention device that can be realized automatically, reliably, and at a relatively low cost.

[Means and actions for solving the problem] Even if humid air contains a certain amount of water vapor, that is, the absolute humidity is constant, as this humid air is cooled, the relative humidity will gradually increase. Finally, the water vapor begins to solidify, leading to condensation.

According to a known humidity chart showing the relationship between relative humidity, absolute humidity, dry bulb temperature, wet bulb temperature, etc., when the relative humidity is 100% or less, the wet bulb temperature T, it is always higher than the dew point temperature T1. , that is, Tm > Tm. This means that if the surface temperature Tsi of the object is T,l > TIE, then “ml
> Tl > Tl holds, therefore Ts
If the condition i > TH is satisfied, of course no condensation will occur on the surface of the object.

The first invention focuses on the above points, and measures the surface temperature T, 1 (1=1.2.3...) of the object to be prevented from condensation,
By comparing the wet bulb temperature TH of the indoor atmosphere at that time, when 'rst<'rH, a warning signal is issued to the outside and necessary measures such as stopping the humidification of the humidifier are taken. The point is that it is designed to prevent the occurrence of condensation.

However, as is clear from the above humidity chart, as the humidity increases, the temperature difference ΔT (TII-T, ) between the wet bulb temperature TH and the dew point temperature T becomes smaller.

The second invention focuses on the above point, detects the surface temperature T□ (t=i, 2 * 3...) of the object to be prevented from dew condensation, and calculates the wet bulb temperature TH of the indoor atmosphere at that time. compared to
At the same time, in order to prevent dew condensation due to a delay in humidity control tracking in high humidity areas, the differential value ΔTDl of the temperature difference ΔT (T□ - TM) is calculated and compared with a preset reference value C. , Ta, (when TH or ΔTDl>C, a warning signal is issued to the outside and necessary measures are taken such as stopping the humidification of the humidifier) to prevent the occurrence of condensation. It is in.

In the first invention, as shown in FIG. 1, for example,
A first thermometer 22 that measures the surface temperature of an object (specimen)
*, 22b and a thermometer 21 that measures the wet bulb temperature of the atmosphere near the object are provided, and the measured values of the thermometers 21 and 22a are compared by a comparator 25 &, and the measured values of the thermometers 21 and 22b are compared. Compare with comparator 25a, each comparison 9525m, 25b
The output of is input to the OR circuit 26, and this OR circuit 26
The output is input to the relay drive circuit 27 to obtain dew condensation prevention information.

The dew condensation prevention information is used in the alarm 1 display, etc., and can provide a warning when the above-mentioned relationship of 9T□<Tlil is established.

In the second invention, in addition to the first invention, as shown in FIG. A differential value comparator 32 that compares with a set reference value and outputs a warning when the rate of change is large is provided to further improve the accuracy of the dew condensation prevention function.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the main part of the first invention, and FIG. 2(b) is an external view and a sectional view thereof.

In FIG. 1, 21 is a wet bulb temperature sensor (second thermometer) that measures the wet bulb temperature of the indoor atmosphere, and its measurement signal is sent to the first . Second
The signal is input to one input terminal of each of the comparator circuits 251 and 25b.

22* and 2jlb are sensors (first thermometers) for measuring the surface temperature of an object, which measure all the surface temperatures at multiple locations on the specimen, and each output is sent to the first thermometer. It is input to the other input terminal of the second comparators 25m and 25b.

The comparators 25m and 21b compare the surface temperature T□ of the object with the wet bulb temperature TH of the indoor atmosphere at that time, and calculate T□(T
This is a circuit that obtains an output signal when it becomes N. Comparator 2
The output of 5% and 25b is input to an OR circuit 26, and the output of this OR circuit 26 is input to a relay drive circuit 27. When the relay drive circuit 27 receives an output from the OR circuit 26, the output relay 28t- is driven, thereby making it possible to output a warning signal to the output terminal 29.

Next, the part that accommodates the 10% control circuit described above will be explained. In FIG. 2, 11 is a stand, and the above-mentioned wet bulb temperature sensor 2) is attached to this stand 11.

Furthermore, there is a wet bulb temperature sensor on stand 11. 211 Multiple terminals 24h for connecting surface temperature measurement sensors 22 & etc.
A terminal 29 is also provided for deriving the output of the output relay 28.

Further, 12 is a cover that covers the control circuit 1o.

In the first invention described above, the operation of the comparator 25a will be explained. The comparator 251 detects the indoor wet bulb temperature TM measured by the wet bulb temperature sensor 21, the object surface temperature T determined by the object surface temperature measurement sensor 22a,
, (1=1), and sends an ON output signal to the OR circuit 26 only when TlK)T, . Similar operations can be obtained with other comparators.

When the output signal of even one of the outputs from the plurality of comparators (two in this example) is on, the OR circuit 26 sends output No. 2 to the relay drive circuit 27, and outputs the output relay 28f.
:Drives and sends a signal to the outside through all output side terminals 29.

In response to this signal, a separate alarm is issued, a humidifier for atmospheric humidity control is stopped, and other necessary measures are taken to prevent condensation from occurring.

Note that in this example, the number of measurement points for the surface temperature Tal is two, but of course the number may be two or more.

FIG. 3 shows an embodiment of the second invention. Most of the configuration is the same as the previous embodiment shown in FIG.

Moreover, FIG. 4(1)(b) is an external view and a sectional view of the second invention. Therefore, the same parts as those in the invention in FIG. 1 will be described with the same reference numerals as in FIG. 1.

In the case of this invention, in addition to the first invention, a differential value comparator 32. It has a reference value generator 30.

The differential value comparator 32 calculates, for example, a temperature difference ΔT (ΔT=T□−
TI) differential value ΔTD, (l=1 in the example shown) t
This ΔTD is compared with the reference fic from the reference value generator 3o set in advance, and an ON output signal is sent to the OR circuit 26 only when ΔTDi>C.The reference value C is This is input from the reference value generator 30 to the differential value comparator 32 via the terminal 31, and the setting is made by the setting resistor 30.
1 (shown in FIG. 4(b)).

The above comparison between the differential value ΔTDl and the reference value C was provided to compensate for the delay in followability of indoor humidity control, which is difficult to deal with only by comparing Tl1t and TH in high humidity regions. It is something. next! IIJI! When the output signal 11161 of the outputs from the comparator 25a for comparing voltages and the differential value comparator 32 is on, the sum circuit 26 performs the following:
Sends the output signal to the relay drive circuit 27 and outputs the output relay 28
and sends signal 2 to the outside through the output terminal 29f.

In response to this signal, a separate alarm is issued, the humidifier for humidity control is stopped, and other necessary measures are taken to prevent condensation from occurring.

In this example, the number of voltage comparators 25a and differential value comparators S2 in the sensor 2 for surface temperature measurement is one each, but of course there may be two or more.

FIG. 4 shows the above-described control circuit 10 mounted on a stand 11. When adjusting the reference value C, cover 1
The second lid 121 is opened and the setting resistor 301 is adjusted.

Note that various embodiments can be realized as a method of using the output of the OR circuit 26 as an output related to prevention of dew condensation. Examples of such information include warnings caused by buds, warning displays, control information for humidity and temperature control devices, and other recorded information.

〔Effect of the invention〕

(,) As a signal, the surface temperature T□ of the specimen (object)
Since the wet bulb temperature of the indoor atmosphere is used (l = 1-2 x 3...), it is possible to automatically and reliably prevent the occurrence of dew condensation.

(b) By detecting the surface temperature T, t of the specimen at multiple locations, it is possible to prevent the occurrence of localized dew condensation.

It is particularly effective for specimens with complex shapes or specimens consisting of multiple parts with different heat capacities.

(C) Since a relatively inexpensive thermocouple with stable performance can be used as the detection end, the cost is low and maintenance is easy.

(d) Since not only the temperature difference but also its differential value is used as a judgment factor, it is possible to compensate for the delay in tracking humidity control even in a high humidity region, and to reliably prevent dew condensation.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the first invention;
Figures (, ) and (b) are an external view and a sectional view of the first invention, respectively, Figure 3 is a configuration explanatory diagram showing an embodiment of the second invention, and Figures 4 (a) and (b) are They are an external view and a sectional view of the second invention, respectively. 10... Control circuit, 11... Unit, 12... Cover, 21... Wet bulb temperature sensor (temperature needle), jj&,
22b...Senna (thermometer) for surface temperature measurement, 25
*. j5b... Comparator, 26... OR circuit, 21...
・Relay drive circuit, 28... Output relay, 3o...
Reference value generation circuit, 32... Differential value comparator, 301...
・Setting resistance. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 2 Figure 4

Claims (2)

[Claims] (1) A plurality of first thermometers that measure the surface temperature of an object, a second thermometer that measures the wet bulb temperature of the atmosphere near the object, and a plurality of first thermometers that measure the surface temperature of the object; a comparator that compares each measured value of the thermometer and outputs an ON signal when the temperature of the second thermometer is high; an OR circuit that ORs the outputs of the comparator; and the OR circuit. A dew condensation prevention device characterized by comprising means for receiving an output of and obtaining a dew condensation prevention related output. (2) a plurality of first thermometers that measure the surface temperature of an object; a second thermometer that measures the wet bulb temperature of the atmosphere near the object; a differential value comparator that calculates a rate of change in the difference between the total and the total value and outputs an on signal when the rate of change is larger than a predetermined value;
A condensation prevention device comprising: an OR circuit into which the output of the differential value comparator is input; and means for receiving the output of the OR circuit and obtaining an output related to condensation prevention.