814-10
September, 2015
MODEL GT814 NOVA-Sensor
ELITE™
Toxic Gas Detector
display REPLACE SENSOR CELL as a reminder that the cell is loosing sensitivity.
After replacing the fuel cell with a new one, hold the UP button depressed for about
2 seconds. The display will read SERVICE ADVISORY CLEARED, and the unit is
ready for another 2 years of operation. Because the sensor cell has been changed,
you should now recalibrate the detector to the new sensor cell.
MAINTENANCE
Monthly “Bump” Tests
We recommend that a short performance test be performed at least every 30 days to verify
that your NOVA-Sensor
ELITE
is operational. This is commonly called a Bump Test in the
industry. During this test, you expose the detector to a small amount of test gas, just enough
to see that the sensor is reading the gas concentration. It is not necessary to perform a com-
plete recalibration of the detector.
During the bump test all of the detector’s outputs (analog and relay contacts) may be activated.
Before starting, notify affected personnel and bypass any shutdowns if required.
The rated maximum reading for your NOVA-Sensor is continuously displayed at the upper
right corner of the screen, such as
100 PPM,
and the target gas is shown on the lower line
of the display, such as
HYDROGEN SULFIDE.
For the bump test, use the target gas mixed
with air at a concentration not greater than the rated maximum PPM.
Expose the sensor head to the bump gas. Watch for the concentration readings to be dis-
played on the detector screen. You do not need to continue beyond this point, you just want
to be sure that there is a response. If you have test gas with concentrations higher than the
alarm trip points, you may leave the gas on until they activate if desired.
Recalibration Schedule
The NOVA-Sensor
ELITE
is pre-calibrated to the target gas at the factory for measuring ranges
up to 500 PPM and no further calibration will normally be required when it is initially installed.
!
NOVA-Sensors with measuring ranges 1000 PPM or higher are not factory calibrated. For
these units follow these instructions to calibrate the sensor after installation and before
placing the sensor in service.
Under normal operating conditions, SST gas detectors should be recalibrated every 90
days. However, the change in calibration over time is a function of how much “background”
gas is present during normal operation, and how often the detector is exposed to higher
concentrations. When the gas sensor is initially installed, we recommend that the calibration
be checked on a more frequent basis to determine how much the calibration is changing. To
check, expose the detector to the same calibration gas as was used for the original calibra
-
tion. Use the data taken over several tests to determine how often you should recalibrate the
detector to keep the desired accuracy.
90 days after the last calibration of the detector was made, the message CHECK CALIBRATION
will be displayed on the screen. This will not effect the normal operation, and the NOVA-
Sensor will continue in normal protection mode using the existing calibration data. However,
the calibration data should be refreshed as soon as practical, using the instructions below.
Summary of Contents for GT814
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