MAN-0148, Rev 1
44
March 2016
SECTION 6: Maintaining
6.1 Periodic response check
Net Safety Monitoring recommends that a bump test be performed every 90 days to ensure continued functionality and
accuracy of the detection system. Full calibration is recommended when the sensor fails to meet acceptable accuracy
standards. This involves the application of calibration gas to the sensor, then the observation of the response LEDs, analog
output, and external monitoring equipment. Be sure to prevent unwanted response of external monitoring devices and
equipment during this procedure. If the Millennium II’s response to calibration gas is within the specified accuracy then it is
not necessary to perform a calibration.
Example:
When 50% of full scale is applied, the response is expected to be between 11.5 mA (47% of full scale) and 12.5 mA (53% of
full scale). An additional consideration is the accuracy tolerance of the calibration gas which may be + or - a few percent. If
the calibration gas is + or - 10% of full scale then the reading may be from 10.7 mA (42% of full scale) to 13.3 mA (58% of full
scale).
6.2 Troubleshooting
Response to the input should be checked and, if necessary, calibration should be performed whenever the accuracy of
this check is not satisfactory. The system should also be checked when sensor or transmitter is added or removed. If
problems should develop, first check for faulty wiring, confirm proper voltage to transmitter and attempt a calibration.
If problems persist, please contact Net Safety’s Service Department first by phone to try and resolve any issues. If
issues cannot be resolved, please follow the procedure on ‘how to return equipment’.