JPS6024487A - Humidity generating apparatus - Google Patents

Abstract

PURPOSE:To enhance measuring accuracy by preventing erroneous addition in using two pressure gauges, by selectively introducing gas from either one of a saturation tank and a test tank into the pressure gauge to store the air pressure value of the test tank, and calculating the gas humidity of the test tank from the air pressure value of the saturation tank. CONSTITUTION:The gas from the saturation tank 25 of a humidity generator 13 is supplied to a pressure gauge 59 through a flowline change-over device 31 to generate voltage corresponding to pressure from an absolute value-voltage converting circuit 60 and the corresponding current value is stored in a divider 64. Subsequently, when the change-over device 31 is changed over, the gas of the test tank 26 of the generator 13 is introduced into the pressure gauge 59 and the current value corresponding to said pressure is similarily supplied to the divider 64 and the stored current value is divided by this current value to calculate the humidity of the gas of the test tank. By this constitution using no pressure gauges at every tank, the error generation in addition due to two pressure gauges is prevented and humidity measuring accuracy is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a humidity generator that generates various types of humid gas necessary for calibrating and inspecting a hygrometer and the like.

A hygrometer that detects the humidity in the air is made so that the actual humidity in the air, which is the object of measurement, matches the humidity obtained by measuring the humidity in the air, at the time of manufacture or at every predetermined period. Calibrated. FIG. 1 is a diagram showing the basic configuration of a two-point pressure type humidity generator, which is one of the humidity generators necessary for calibrating such a hygrometer. As shown in this figure, this humidity generation device includes a humidifying tank 1 that generates pressurized high-humidity air A1, and the high-humidity air A from this humidifying tank 1 to produce saturated air with a humidity of 100%. The inside of the tank is filled with a saturation tank 2 that produces air A2, a pressure regulating valve 3 that expands the saturated air A2 from this saturation tank 2 at a desired pressure ratio, and expanded air A3 sent out from this pressure regulating valve 3. a test tank 4, this test tank 4 and the saturation tank 2,
It has a constant temperature bath 5 that keeps the pressure regulating valve 3 at a constant temperature, and if the pressure of the saturated air A2 is Ps and the pressure of the expanded air A3 is pt, then the expanded air filling the test chamber 4 is The humidity H (a) of A3 is determined by pt H=--X 100 (1) Ps. Therefore, by changing the degree of opening of the pressure regulating valve 3 depending on the desired humidity, air with the desired humidity can be generated in the test chamber 4.

In this way, the humidity generator calculates the humidity H of the expanded air A3 generated in the test tank 4 from the pressure Ps on the saturation tank 2 side and the pressure pt on the test tank 4 side. Since the pressure in the tank 2 was measured with the first pressure gauge 6 and the pressure in the test tank 4 was measured with the second pressure gauge 7, for example, as shown in FIG. 7, the output characteristic line of the pressure gauge 6 deviates upward from the normal line S1 and becomes the line S2, and at this time the output characteristic line of the pressure gauge 7 deviates downward from the line S1. When the line S3 is reached, the detection errors Gl and G2 are added, and the measurement error may become large.

In view of the above points, this invention enables the pressure on the saturation tank side and the pressure on the test tank side to be detected with one pressure gauge, and thereby eliminates the addition of errors that occur when two pressure gauges are used. The purpose of the present invention is to provide a humidity generating device that can prevent humidity and improve its measurement accuracy.

In order to achieve these objectives in the humidity generator according to the present invention, either one of the gas in the humidifying tank and the gas in the test tank in the two-point pressure type humidity generating tank is selected and the pressure gauge is set. A flow path switching device to introduce the gas, and a pressure value obtained when this flow path switching device introduces the gas from the test tank to the pressure gauge, and the pressure value and the flow path switching device memorize the saturated gas. The present invention is characterized by comprising a calculation circuit that calculates the humidity of the gas obtained in the test tank from the pressure value obtained when the gas in the tank is introduced into the pressure gauge.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 3 is a diagram showing a humid air generation mechanism of the humidity generation device according to the present invention. In this figure, the reference numeral 10 is a humidification tank that generates high-humidity air, and the pre-pressurized air supplied via the air filter 11 is used for this humidification +7! After being made into high humidity air by i 10, it is sent to humidity generator 1 through pipe 12.
3. Further, reference numeral 14 is a dry air generator that generates dry air, and the air supplied through the pipe 15 is first filtered with dust and the like by an air filter 16 in this dry air generator 14, and then 1 cooling type air dryer (for example, an air dryer with a dew point of -20°C) 17, and then drying by the cooling type air dryer 17 of cylinder 2 (for example, an air dryer with a dew point of -20°C).
For example, the degree of dryness can be further increased by using an air dryer (18) with a dew point of -72°C. Next, the dryness of the thus obtained highly dry air (air with a humidity of approximately 0%) is displayed by an indicator 19 and is supplied to the humidity generator 13 via a pipe 20. . The humidity generator 13 includes a cylindrical outer cylinder 21 and this outer cylinder 2.
An upper plate 22 and a lower plate 2 provided at the upper and lower ends of 1, respectively.
3, a rectifying cylinder 24 disposed inside the outer cylinder 21 concentrically with the outer cylinder 21, a saturation tank 25 provided in the middle of the rectifying cylinder 24, and a saturation tank 25 provided on the central axis of the rectifying cylinder 24. It has a test tank 26 in which the i4 ID 1 is
The high-humidity air supplied through the straightening tube 24 is connected to water (or other liquid) 28 that is filled in the outer tube 21 by the first soaking tube 27 spirally wound around the outer peripheral surface of the straightening tube 24. After the air is brought to the same temperature as the air, it is supplied to the saturation tank 25, where excess water is removed to make saturated air with a humidity of 100 degrees, and the air is supplied to the saturation tank 3o. saturation iu
One side of the ide 30 is connected to the first inlet 32 of a second flow path switching device (for example, a three-way valve) 31 provided in the row of the outer cylinder 21, and the other side is connected to the first inlet 32 of the second flow path switching device (for example, a three-way valve) 31 provided in the row of the outer cylinder 21. The outlet port 35 of the pressure regulating valve 33 is connected to the inlet port 34 , and the outlet port 35 of the pressure regulating valve 33 is connected to the first flow path switching device 3 via the pressure regulating valve 36 .
It is connected to the first inlet 38 of No. 7. Mata no de Eve 2
The dry air from the dry air generator 14 that is supplied through the
After the temperature of the water 28 is brought to the same temperature as that of the water 28 by a second soaking pipe 39 spirally wound between the water 7 and the water 28, the second flow of the first flow path switching device 37 is passed through a pipe 40. It is supplied to the inlet 41. The first flow path switching device 37 has its flow path switched off by a lever 42, and when it is in the position shown in the figure, the humid air (the saturated air The air (obtained by expanding the After this, the feed is supplied into the test chamber 26 through the tube 45, and the lever 42 is moved from this position to the right side (
When it is knocked down to the right side in the figure, the second inlet 41
The dry air supplied to the test chamber 26 is supplied into the test chamber 26 by sequentially valves the d'ide 43 and the third soaking tube 44% mode 45.

Therefore, if the pressure ratio of the pressure regulating valve 33 is changed from 1=1 to 1:5 with the lever 42 set to the position shown in the figure, the humidity in the test chamber 26 will change from 100 degrees to 20 degrees.
%, and by tilting the lever 42 to the right from the position shown in the figure, the test chamber 2
It is possible to generate air with a humidity of 0% within the room. In this case, the motor 50 rotates the stirring blades 51 provided in the lower part of the outer cylinder 21, so that the water 28 flows through the rectifying plate 52a attached to the inner surface of the rectifying cylinder 24.
~ 52f, and then guided to the outer surface side of the rectifying tube 24 at the upper part of the rectifying tube 24 and moving downward,
Next, the flow rows 53a~ provided at the lower part of the rectifying tube 24
53n, returned to the stirring blade 51 side, and moved upward again, the water 28 has a uniform human temperature as a whole regardless of its position.

On the other hand, the air (test air) in the test tank 26 is discharged through the outlet passage 55.
and is supplied to the second inlet 57 of the second flow path switching device 31 via the guide 156. The second flow path switch 31 is the same as the first flow path switch 37.
Similarly, the flow path is switched by a lever 58, and when it is in the position shown in the figure, the test air supplied via the nozzle 56 is supplied to the pressure gauge 59, and from the position shown in the figure. When it is knocked down, the pipe 3
The saturated air supplied through the pressure gauge 59 is supplied to the pressure gauge 59 and converted into a corresponding electrical signal.

The circuit for processing the output of the pressure gauge 59 will be described in detail below with reference to the block diagram shown in FIG. First, when the 20th flow path switching device 31 supplies the test air in the test tank 26 or the saturated air in the saturation tank 25 to the pressure gauge 59, the pressure gauge 59 detects the test air (or saturated air). Converts the pressure into the corresponding current signal S10 to obtain the absolute pressure/
The voltage is supplied to the voltage conversion circuit 60. Absolute pressure/voltage conversion circuit 6
0 (hereinafter referred to as zA/V conversion circuit 60) converts the current signal SIO into a voltage signal Sll, and this voltage signal Sll is supplied to the display device 62 via the first switch 61. The pressure value is displayed, and a current signal S having a value corresponding to the magnitude of the variable resistor 63 is displayed.
It is supplied to the input terminal 64a of the divider 64 as i2. The divider 64 divides a constant by the value of the current signal S12 supplied to its input terminal 64a;
This division result is output as a voltage signal 813 and is also supplied to the display device 62 via the second switch 65. In this way, the divider 64 in this circuit performs the calculation Vout = T - (21) and outputs the voltage Vout, so the second flow path switch 31 selects the test air. Voltage signal 8 obtained when supplied to pressure gauge 59
The value of the variable resistor 63 is set according to the value of R=α・Pt (
α is a constant), the second flow path switch 31 selects saturated air, and the A/V conversion circuit 60 generates a voltage corresponding to the pressure Ps of this saturated air (V-β・Ps). When the voltage signal Sll' (i = ratio output), the value ■
A current signal S12 of (■-y) is supplied, and a voltage signal S13 having a value indicated by is outputted from the dividing circuit 64.し=straddle the above constant ′! If it is set to 1l - K o x 100, the above formula (3) becomes t Vout = -X 100 - (41s), and the humidity of the test air generated in the test tank 26 is displayed on the display device 62. - Can be displayed in cents.

In this case, the pressure in the test tank 26 is the same as atmospheric pressure, which has a gradual pressure fluctuation, so once the pressure in the test tank 26 is set to the variable resistor 63, the pressure in the saturation tank 25 can be continuously detected. can do.

Also, in this case, since the pressure in the test tank 26 and the pressure in the saturation tank 25° are measured by one pressure gauge 59, the errors that occur when each pressure is measured individually with two pressure gauges are added. In addition, the structure can be simplified and the cost of the entire device can be reduced.

FIG. 5 is a block diagram showing another example of the circuit configuration of the humidity generator according to the present invention. The circuit shown in this figure is different from the circuit shown in FIG. 31, variable resistor 63, first switch 61, second switch 65, and display device 62. Therefore, in this case, if the humidity setting circuit 70 is set to, for example, 50% humidity, the humidity control circuit 71 causes the tenth channel switch 37 to select saturated air, and the second channel switch 31 selects saturated air. The test air in the test tank 26 is selected, and the first switch 61 is closed at this time, and the value at this time is displayed on the display device 62 in the test tank 2.
Display the pressure as 6. Next, the humidity control circuit 71
When the second switch 65 is closed, the output of the divider 64 is supplied to the display device 62, and the percentage display at this time (actually blank and not displayed) becomes 100%.
After controlling the value of the variable resistor 63 so that A voltage signal S11 of the value is output. and divider 6
The value of the voltage signal S13 output from the humidity setting device 70
The humidity control circuit 71 controls the pressure regulating valve 33 until the humidity reaches the value set by .

Further, if the humidity setting unit 70' sets the humidity to 0, for example, the humidity control circuit 71
to select dry air, and the second switch 65
is opened to cut off the connection between the divider 64 and the display device 62, and at this time a signal indicating humidity 0%e is supplied to the display device 62 to display it.

Even if each part of the apparatus is controlled by the humidity control circuit 71 in this manner, the same effects as those described above can be obtained.

Furthermore, in each of the embodiments described above, the pressure inside the test chamber 26 is memorized by the variable resistor 63;
This may be stored in analog form using sample and hold, or may be stored as a digital signal through A/D conversion (analog/digital conversion).

Furthermore, in the above explanation, either saturated air or dry air is selected by the tenth flow path switch 37, but a flow control valve is provided in this part to adjust the humidity of the test air from zero to zero. It may be made to be continuously variable up to 100%.

Furthermore, if a heater is provided in the lower part of the outer cylinder 21 as necessary, the temperature of the water 28 can be controlled, and test air having desired humidity and temperature can be obtained.

As explained above, the humidity generator according to the present invention is provided with a flow path switching device that selects either the gas from the high humidity gas generator or the gas from the test tank and introduces the selected gas into the pressure gauge. The pressure value obtained when the switching device introduces the gas from the test tank into the pressure gauge is stored in an arithmetic circuit, and the arithmetic circuit converts the pressure value and the flow path switching device into the high-humidity gas generation. Since the humidity of the gas obtained in the test tank is calculated from the pressure value obtained when the gas in the container is introduced into the pressure gauge, the humidity can be measured with one pressure gauge. The cost can be reduced and the structure can be simplified. Further, it is possible to prevent the errors of each pressure gauge from being added, which occurs when a plurality of pressure gauges are used, and the measurement accuracy can be improved.

[Brief explanation of the drawings] Figure 1 is a schematic diagram showing an example of a conventional humidity generator, Figure 2 is a schematic diagram showing an example of a conventional humidity generator.
The figure is a characteristic diagram for explaining measurement errors in such a humidity generator, FIG. 3 is a sectional view showing an embodiment of the humidity generation mechanism of the humidity generator according to the present invention, and FIG. 4 is a diagram showing the same embodiment. FIG. 5 is a block diagram showing another example of the circuit structure of the same embodiment. 10... Humidification tank, 14... Dry gas generator (dry gas generator), 25... Saturation tank, 26... Test tank, 3
0゜36.40.43... Riya Eve (channel), 31...
・Second flow path switching device (flow path switching device), 33... Pressure adjustment valve, 37... First flow path switching device (flow path switching device), 5
9...Pressure gauge, 60...Absolute pressure/voltage conversion circuit, 6
3... Variable resistance (arithmetic circuit), 64... Divider (arithmetic circuit), 71... Humidity control circuit # (control circuit).

Claims (2)

[Claims] (1) In a two-point pressure type humidity generator, the flow path switching device selects either the gas in the saturation tank or the gas in the test tank and introduces the selected gas into the pressure gauge. The pressure value obtained when the gas in the test tank is introduced into the pressure gauge is stored, and the pressure value and the pressure value obtained when the flow path switch introduces the gas in the saturation tank into the pressure gauge are stored. and a calculation circuit that calculates the humidity of the gas obtained in the test tank from the above. (2) The output of the arithmetic circuit is supplied to a control circuit, and is compared with a desired humidity set in advance in this control circuit, and the 1ffi pressure regulating valve is controlled based on the comparison result. A humidity generating device according to claim 1.