JPH04339256A - Gas concentration measuring apparatus - Google Patents

Abstract

PURPOSE:To automativcally measure the concn. of gas by a gas concn. detecting part. CONSTITUTION:Solenoid valves 3a, 3b, 3c are respectively provided to a plurality of gas concn. detection parts 1a, 1b, 1c to be connected to an air pump 2 and the opening and closing of the solenoid valves 3a, 3b, 3c and the operation of the air pump 2 are controlled by a control means 10. The concn. of specific gas can be automatically detected without requiring labor and can be easily measured even in the case of low concn.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas concentration measuring device, and more particularly to a gas concentration measuring device that automatically detects the concentration of a specific type of gas present in the air.

0002

2. Description of the Related Art Conventionally, it has been widely practiced to check the concentration of CO2 in indoor air, and to check the concentration of ethylene gas generated from fruits, vegetables, etc. in order to check the degree of ripeness of the fruits, vegetables, etc. To detect such gas concentration, an apparatus as shown in FIG. 4 is used. This device has a gas concentration detection section 31 filled with a gas detection agent 33 connected to the tip of a piston 30, and a piston rod 3
2 is subtracted, gas-containing air is sucked into the gas concentration detection section (gas detection tube) 31 (indicated by arrow A), and the gas concentration is measured by the discoloration length of the gas detection agent 33 filled inside. was.

0003

However, the above-mentioned gas concentration measuring device requires manpower, and it is difficult and complicated to measure the gas concentration at regular intervals. In particular, in conventional gas analysis using a manual suction pump, the gas concentration is measured by sucking 100 ml of gas once or twice each time. The length may be too small to read. In such a case, the gas concentration is measured by increasing the number of gas suctions and lengthening the discoloration length of the gas detection agent 33. At this time, the gas concentration according to the length of discoloration is usually scaled by the length of discoloration in one suction amount (usually 100 ml), so the gas concentration is expressed by the following equation.

[0004] Gas concentration = Gas concentration depending on length of discoloration / Number of suctions (However, there is also a scale with two suctions (200ml).) Therefore, if the gas concentration is low, suction must be performed multiple times. Therefore, it was very troublesome. The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide an automated gas concentration measuring device that can easily detect gas concentration at any arbitrary time without requiring human labor. purpose.

[0005]

[Means for Solving the Problems] The gas concentration measuring device of the present invention includes a plurality of gas concentration detection sections for detecting the concentration of inhaled gas, and a plurality of gas concentration detection sections connected in parallel to each other. An air pump that sucks air into the gas concentration detection section, a solenoid valve for opening and closing the flow path provided between the air pump and each of the gas concentration detection sections, and a corresponding one for each gas concentration detection section. The invention is characterized by comprising control means for controlling the opening and closing of the electromagnetic valve and the operation of the air pump.

[0006]

[Operation] According to the present invention, since the control means controls the opening/closing time of the solenoid valve (therefore, the gas suction time of the gas concentration detection section) and the operation time of the air pump in conjunction with this, the plurality of gas concentration detection sections By setting the solenoid valves attached to each unit to operate sequentially at regular intervals, gas is sequentially sucked into the gas concentration detection unit connected in parallel to the air pump, and the gas concentration can be automatically detected. can.

In particular, even if the gas concentration is so low that the length of discoloration of the gas concentration detection section cannot be read, this can be easily dealt with by setting the gas suction time longer accordingly. For example, if the gas concentration is low, the amount of gas (500 ml) is 5 times the amount of suction (100 to 200 ml) per suction.
~1000 ml) can be aspirated to measure the gas concentration.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing a gas concentration measuring device according to the present invention. As shown in the figure, this gas concentration measuring device has three tubular gas concentration detection sections 1a, 1b, and 1c connected to a suction air pump 2 in parallel. The connection is made using a stainless steel pipe 4 that branches into three parts. Furthermore, electromagnetic valves 3a, 3b, and 3c are connected to the rear ends of the gas concentration detection units 1a, 1b, and 1c, respectively. Each of the gas concentration detection units 1a, 1b, and 1c utilizes the fact that the tube is filled with a gas detection agent 11, and the length of discoloration of this gas detection agent changes depending on the gas concentration.

The connections between the pipe 4 and the solenoid valves 3a, 3b, 3c and the connections between the solenoid valves 3a, 3b, 3c and the gas concentration detection sections 1a, 1b, 1c are made using rubber tubes 5, 6 (silicone rubber tubes). etc.). A needle valve 7, a flowmeter 8 for visually checking the presence or absence of air flow, and a flowmeter 9 (wet flowmeter, etc.) for measuring the amount of air passing through are connected in this order to the air discharge side of the air pump 2. has been done.

The solenoid valves 3a, 3b, 3c, the air pump 2 and the flow meter 9 are electrically connected to a control section 10,
Control these operations. The operation of the gas concentration measuring device of the present invention will be explained below. In the state shown in FIG.
The solenoid valve 3a opens in response to a signal from the other solenoid valve 3b.
, 3c is closed and the air pump 2 starts operating.
Air is sucked in the gas concentration detection section 1a connected to the electromagnetic valve 3a (indicated by arrow A), and the gas detection agent changes color to a predetermined length according to the gas concentration contained in the air. This measures the gas concentration in the air. The suction amount is measured by a flow meter 9, and when the suction amount reaches a set value, the control unit 10 receives a signal from the flow meter 9, and
A signal is sent to the solenoid valve 1a to close the solenoid valve 1a, and at the same time, the operation of the air pump 2 is also stopped.

After a predetermined time has elapsed, the next solenoid valve 3b opens,
The air pump 2 starts operating again, causes the next gas concentration detection section 1b to suck in the air containing the gas to be tested, and the test is performed in the same manner as described above, and after sucking in a predetermined flow rate, the solenoid valve 3b is closed. Hereinafter, similar operations are performed for the gas concentration detection section 1c. These operations are shown in FIG. FIG. 2 shows a time chart from the start of operation to the stop of the gas concentration measuring device according to this embodiment.

[0012] The amount of air suction can be set arbitrarily. Similarly, the operation time of the suction air pump 2, each solenoid valve 3a
, 3b, 3c can also be arbitrarily set by the control unit 10 according to the gas concentration in the air, etc. According to the gas concentration measuring device of this embodiment configured as described above, it is possible to automatically analyze the gas concentration up to 1/5 of the scale provided on the tube wall of the gas concentration detection section.

[0013] In this embodiment, the solenoid valves 3a, 3b,
3c is provided on the suction side of the gas concentration detection sections 1a, 1b, and 1c, but it may be provided on the opposite suction side as shown in FIG. Furthermore, the number of gas concentration detection sections connected in parallel to the air pump 2 is not limited to three, and any number of gas concentration detection sections can be connected.

[0014]

[Effects of the Invention] According to the present invention, it is possible to automatically detect the operation of measuring the concentration of a specific gas by the gas concentration detection section, and even when the gas concentration is particularly low, it can be easily detected. This has the effect of making it possible to save labor in measurement.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a gas concentration measuring device according to an embodiment of the present invention.

FIG. 2 is a time chart of operations in the gas concentration measuring device.

FIG. 3 is an explanatory diagram showing another state in which the electromagnetic valve is attached to the gas concentration detection section.

FIG. 4 is a partially cutaway front view showing a conventional gas detection device.

[Explanation of symbols]

1a Gas concentration detection part 1b Gas concentration detection section 1c Gas concentration detection section 2 Air pump 3a Solenoid valve 3b Solenoid valve 3c Solenoid valve 10 Control section

Claims (1)

[Claims] Claim 1: A plurality of gas concentration detection sections (1a, 1b, 1
c) and the plurality of gas concentration detection units (1a, 1b, 1c
) are connected in parallel to each other to suck air into each gas concentration detection section; this air pump (2) and each of the gas concentration detection sections (1a, 1);
solenoid valves (3a, 3b, 3c) for opening and closing flow paths provided between the respective gas concentration detection units (1a
, 1b, 1c) corresponding solenoid valves (3a, 3b, 3c)
1. A gas concentration measuring device comprising: control means (10) for controlling the opening and closing of the air pump (2) and the operation of the air pump (2).