in the process of using combustible gas alarm, due to various reasons, sometimes combustible gas alarm will appear the phenomenon of zero drift, although this phenomenon has not yet reached the damaged state, but may lead to combustible gas The resistance value of the detection element of the alarm becomes irreversible, resulting in the change of reversal leading to the imbalance of the bridge output, resulting in zero drift. Then do you know the causes of combustible gas alarm zero drift and what are the treatment measures? The following is a brief introduction by yi yun Tian:

combustible gas alarm zero drift causes and treatment measures:

1. Some combustible gas alarm manufacturers use fixed voltage bridge power supply mode. In this way, because the line resistance changes with the change of atmospheric temperature, the zero point drift of the instrument is caused, which brings additional indication error. Therefore, the constant current bridge method can be used to eliminate it.

2. the alarm zero point of combustible gas may be due to the influence of high concentration of combustible gas, and the resistance value of detection element d changes irreversibly, resulting in zero drift caused by unbalanced bridge output.It can be processed as a zero output by the zeroing circuit of the control unit. If the unbalanced output increases to 20% of full scale and the zero output of the control unit cannot be adjusted to zero, the sensor assembly needs to be replaced.

3. the rain cover of the combustible gas alarm is not cleaned regularly, and oil and fog droplets condense, resulting in the accumulation of combustible gas near the probe of the combustible gas alarm, resulting in zero drift. At this time, the dirt accumulation should be cleaned. The cleaning process must be clean and no residual solvent (do not use solvents such as gasoline and acetone). It can be soaked in anhydrous alcohol and washed and dried with clean water many times. When the rain cover is damaged or there is no rain cover, it should be replaced and installed in time.

To sum up, it is the cause of the zero drift of the combustible gas alarm and the treatment measures. In order to better avoid the zero drift of the combustible gas alarm, we should regularly overhaul the explosion-proof facilities and find that there is damage, such as damage to the explosion-proof seal, looseness, rupture of the explosion-proof hose, looseness of the fastening bolt or rupture of the explosion-proof threaded box, etc. Repair or replace.