Multi gas detector structures: multi gas detectors consist of a gas-tight piston and aluminum alloy gas storage tube. It is mainly used to quickly check the concentration of carbon monoxide in the ambient air of coal mines. It can also be used together with different types of gas detector tubes to determine the concentration of various gases such as carbon dioxide, hydrogen sulfide, oxygen, and nitrogen dioxide.

In order to make the multi gas detector work better, we need to pay attention to the following methods during use:

First,Preparation before going down the well:

1. Check that the outer casing and the connecting part are in good condition and that the joint hose is equipped;

2. Check if the air path is unblocked: Pull the piston in parallel with the three-way switch and the cylinder to check the air inlet, and hang the three-way switch and the cylinder

The straight device pushes the piston to check the air outlet;

3. Check the flexibility of the piston: reciprocally push and pull the piston 3-4 times in parallel with the three-way switch and the cylinder to make it flexible;

4. Check the air tightness: twist the three-way switch to a 45° angle with the cylinder, pull the piston, pull it quickly, and quickly restore or live the piston.

The scale on the plug back to no more than 5ml indicates good air tightness.

5. Not less than 30 types of verification tubes;

6. Check the integrity of the verification tube, the maximum value of the verification tube, the prescribed air supply time, the prescribed air supply amount, type, and service life.

Second, the multi gas detector actual operating procedures:

Arrive at the location to be tested, parallel the device with the three-way switch and the cylinder, take the air from the upper part of the roadway, push and pull the piston 3-4 times to clean the piston.

Pull out slowly the last time, then quickly twist the three-way switch to a 45° angle to the barrel. Take a longer test tube, first

Observe the specified air supply and air supply time of the identification tube, open both ends of the verification tube, the zero position is facing downward, and the scale is facing itself.

The verification tube is inserted into the joint hose, and then the three-way switch is twisted into a vertical position with the cylinder, and the air is supplied at a constant speed within a predetermined time.

The position where the color changing ring moves. The concentration of carbon monoxide is read according to the actual moving scale on the verification tube.

Three inspections multi gas detector:

1. Constant check: The operation method is the same as above, the specified air supply amount can be sent at a constant speed within the specified time, and the direct reading can be performed on the verification tube.

As a constant, the concentration of carbon monoxide is the value displayed by the verification tube.

2. Micro-inspection: The operation method is the same as above. After the specified air supply volume is delivered at a constant speed within the specified time, the test tube cannot read.

Take the same method to use the same test tube to repeatedly send air to check, the amount of gas is the same every time, the inspection results

The result is divided by the number of aspirations, which is the true content.

Namely: carbon monoxide concentration = reading on the verification tube / number of air supply

3. Concentration check: The operation method is the same as above, and the air is supplied at a constant speed within the specified time. When the specified air supply volume is not reached, the verification tube has reached

To the maximum value, the concentration of carbon monoxide at this time = the maximum value of the test tube × the prescribed air supply amount / the actual air supply amount. High concentration of mono-oxidation

Carbon can be inspected after thinning, and the result is multiplied by a thin multiple, which is the true content.

Precautions

1. In the case of constant check, the test tube is 100ml, and the test tube with air supply time of 100 seconds or 200 seconds needs to be sent out.Gas is the true concentration of the gas to be tested.

2. For traces and concentrations of carbon monoxide, the test tube of the corresponding measurement range should be selected for measurement.

3. When detecting gas, first observe the expiration date and measurement range of the verification tube. Understand the value represented on the verification tube .The concentration is tested according to the verification tube instructions. (Generally carbon monoxide, carbon dioxide, oxygen are 50ml; hydrogen sulfide is 100ml, 100 seconds; nitrogen dioxide is 50ml, 25 seconds)

4. If the gas nozzle is blocked, the valve can be pulled into the vertical position of the cylinder, the gas sample is removed from the air outlet, and then pulled into a 45° rear insert.Verify the tube and pull it into a vertical position to send the gas out.

5. Conversion relationship between percentage and ppm 1% = 10000 times the ppm value