A. There are a number of factors that can lead to your monitor moving off zero.
1. A drastic or sudden changes in temperature or pressure. The technology of the sensors within your personal gas detector may cause some fluctuation when this occurs.
2. Sensor poisoning or exposure to cross-reference materials.
Common Sources of Poisoning
Thankfully, if your monitor does move off zero due to any one of these factors, you can perform a fresh air zero to reset the sensors.
Fresh Air Zero GasAlert MicroClipXT
Fresh Air Zero GasAlert Quattro