9
GG-NH3
Maintenance
The GG-NH3 sensor is designed for long life and
minimal maintenance. For proper operation, it is
essential that the test and calibration schedule be
adhered to. Calibration Technologies recommends the
following maintenance schedule:
Maintenance Guidelines:
• The sensor is shipped with a factory calibration.
• Sensor should be calibrated 6 months from
purchase date.
• Calibrate the detector at least once every 6 months.
•
Calibration should be performed with certified
calibration gas. Calibration kits and replacement
cylinders are available from CTI.
• All tests and calibrations must be logged.
• Always disconnect power at the controller before
performing any wiring at the sensor.
Sensor Life:
The electrochemical cells are extremely
reliable, but several things can cause depletion of the
chemistry within the cell including:
• A period of time
• Exposure to high temperatures
• Continuous, long term exposure to ammonia
When the SafeCell test fails, the fault (red) LED will
blink once per second. After six hours of continued
and consecutive test failures, the 4-20 mA signal
output will drop to 0.5 mA and the fault LED stays on
solid. This signal should be interpreted as a sensor
fault at the control panel and prompt notification to
plant personnel to investigate the sensor.
SafeCell technology tests the electrical viability of the
cell, however, it does not confirm proper sensitivity
to gas.There are other factors that could prevent the
cell from detecting gas, such as physical blockage, etc.
Therefore,
it is absolutely essential that the sensor be
calibrated every six months.
Typical cell life is 2 to 5 years. When the cell becomes
depleted, a replacement cell can be obtained from
CTI. Simply unplug the cell's ribbon cable from the
transmitter, pull the old cell from the spring clip,
discard the old cell and replace with a new one.
The new cell can be span-calibrated immediately.
However, an 8 hour warm-up period is required
before zeroing, if necessary.
Replacement cell order#
:
