How to test the 4-in-1 gas detector

　　The control 4-in-1 gas detector uses a special type of circuit that measures the current at two points within the detector. When combustible gas enters the circuit chamber, one half of the circuit is warm enough to ignite the gas, and it contains a or combustion catalyst. When the gas burns, the current in the test zone changes, and the heat and electricity flowing through the circuit are changed. This change triggers the alarm device.

　　Infrared combustible gas detectors work in a completely different method. As gas enters the test chamber, a beam is emitted by it. It actually reaches the gas; half goes into a receiver for the gas, and the other goes back to the transmitter. The detector measures the intensity of both beams to determine if combustible gas is present. When the beams are identical, everything is fine, but variations in beam intensity on the gas side could mean that something is wrong.

　　Gas detectors are used with caution in toxic gas detection. First, we must be aware of the inherent problems: based on the characteristics of toxic gases being chemically stable and at a relatively high concentration level, the response time is generally slow because they rely on air flow rather than actively pulling the sample. Calibration of four-in-one gas detectors is often difficult and requires special accessories to convert the flow-through calibration purpose to a diffusion mode of operation. In addition, the equivalence between flow-through monitoring and calibration is not always well documented.

　　Secondly, calibration can be further complicated if adjustments must be made at the control panel while gas is being applied to the remote diffusion gas detector sensor head . In some applications, interfering gases may be present. The sample draw method allows a chemical scrubber to be placed upstream of the sensor to absorb the interfering agent. All gas sensors measure partial pressure, and the sample actively drawn to the sensor is at a slightly elevated pressure, whereas diffusion sensors operate at ambient pressure. Therefore, sample draw sensor output sensitivity is typically higher than that of diffusion sensors. This can be important for many toxic gases with low regulatory levels. But there will be no need to characterize how many toxic gases there are.

　　Toxic gas leaks at processing plants pose a danger in many industries, including chemical, oil/gas, electric utilities, food and beverage, pharmaceutical, pulp/paper, and wastewater. Leak sources typically include pipes, valves, tanks, burners, chillers, separators, lighting systems, aeration tanks, and other equipment.

　　A combustible gas detector is a device that senses hazardous gases and alerts people to the presence of danger. There are two main methods for detecting combustible gases: controlled combustion and infrared technology. Each of these methods has its own advantages and disadvantages, although the infrared method is generally safer overall. In addition to the 4-in-1 gas detector, there is a group of other devices that detect non-combustible hazardous gases.