Possible causes and solutions 1. The atmosphere in which the instrument is located is contaminated or was contaminated at the time the instrument was last fresh air calibrated. Anew sensor has just been installed.
IQ Force™ Gas Detector Reference Manual 29 Fresh Air/Zero Calibration 3. Instrument has been dropped or otherwise damaged since last turned on. There has been a significant change in temperature since the instrument was last used. Recommended action: Take the instrument to fresh air and allow readings to stabilize. Perform the fresh air/zero adjustment again. If the fresh air/zero procedure fails to correct the problem, perform the manual fresh air/zero calibration procedure as described in Section 4.2.2 below. 4.2.2 Manual fresh air/zero calibration The IQ Force includes safeguards to prevent fresh air calibration in contaminated environments. If the standard fresh air/zero calibration fails a second time, the instrument maybe forced to accept the fresh air calibration by performing the manual fresh air/zero calibration.