What degree of accuracy should I expect from a properly calibrated gas detector?
A. Gas detectors designed to operate in automatic ventilating systems use three basic types of sensors. Detectors using the older solid state sensors can obtain an accuracy of +/- 10 percent of the full scale response. This type of sensor is rapidly being replaced by the electro-chemical type of sensor. This sensor can easily obtain an accuracy of +/- 5 percent of the full scale response. Some detectors use the “near infra-red” principle of measurement to monitor the target gas. This type of detector can obtain an accuracy of +/- 2 percent, and in some cases, reach a short term accuracy of +/- 1 percent. The “near infra-red” detectors are the most costly. Brasch gas detectors use the electro-chemical type of sensor to obtain better than required accuracy along with low cost.
