Det-Tronics U9500 Infiniti Gas Transmitter - Manual (Page 29)

95-8444 27 10.1
Routine Calibration Procedure
1. Do not remove the C7065E sensor cover.
2. Apply the calibration magnet to the U9500 calibration
target location for nine seconds, or until the U9500
display shows “zero-cal”. The initial zero baseline
output level reading will be referenced. Wait until the
U9500 display shows “aply-gas”.
3. The transmitter will now begin to record the sensor
output level in response to the ambient oxygen
concentration. If this is known to be 20.9%, an
accurate span calculation will result. If the ambient
O
2
level is less than 20.9%, it is recommended
to apply 20.9% oxygen using a Det-Tronics O
2
calibration kit.
4. When span calculations are complete, the U9500
display will indicate “cal-OK”, and then “rmv-gas”.
If using a Det-Tronics O
2
calibration kit, remove the
calibration cup and close the regulator valve. No
actions are necessary if ambient air O
2
is used.
5. The U9500 will automatically exit calibration mode
when calibration is complete. The displayed O
2
level
should be 20.9% (17.4 mA current level) if ambient
conditions are normal.
CGS SENSOR REPLACEMENT
Under certain circumstances, an existing U9500A
Infiniti gas transmitter fitted with a replacement CGS
sensor may not exit “warm up” mode after four minutes
from power up, causing a “Zero Drift” indication to be
displayed on the U9500A. This uncommon situation can
occur when a CGS pellistor resistance is slightly offset
from the previous CGS pellistor resistance. It does not
mean that the sensor or the Infiniti transmitter are bad or
out of tolerance.
There are two simple methods to solve this problem.
Preferred method:
This method requires a Hot Work Permit and
declassification of the work area.
1. Disable any alarming devices triggered by the
U9500A Infiniti transmitter alarm outputs.
2. Power up the U9500A with a new or different CGS
sensor installed.
3. Wait for the U9500A Infiniti transmitter to display
“Zero Drift” indication (approximately 4 minutes
from power up).
4. Remove the cover from the Infiniti transmitter.
5. While the Infiniti transmitter display is indicating “Zero
Drift,” simultaneously press and release the Increase
and Decrease switches on the Infiniti faceplate. The
Infiniti will exit the warm up mode and display an
incorrect gas level reading.
6. Calibrate the U9500A following the “Initial/
Replacement Sensor Calibration” procedure.
7. Replace the Infiniti J-box cover.
8. Re-enable any alarming devices triggered by the
U9500A Infiniti alarm outputs.
Alternate method:
This method can be used in a classified/hazardous area.
1. Disable any alarming devices triggered by the
U9500A Infiniti transmitter alarm outputs.
2. Power up the U9500A with a new or different CGS
sensor installed.
3. Wait for the U9500A Infiniti transmitter to display
“Zero Drift” indication (approximately 4 minutes
from power up).
4. Apply calibration gas to the sensor. After
approximately 30 seconds, the U9500A will reset,
go through the startup cycle, and display some
incorrect gas level.
5. Apply a calibration magnet and hold it in place until
the Infiniti transmitter enters the calibration mode.
The Infiniti display will read a gas indication number
alternating with “Zero Cal”.
6. Remove the calibration gas from the sensor.
7. Allow the Infiniti to zero calibrate to the new or
different sensor.
8. When prompted by the Infiniti, apply the calibration
gas to set the 50% LFL span setting.
9. Once the Infiniti accepts the new span setting, follow
the prompts to exit the calibration mode.
10. From this point, allow the sensor to fully warm up for
one hour minimum, and then calibrate the U9500A
following the normal calibration procedure in the
instruction manual.
11. Re-enable any alarming devices triggered by the
U9500A Infiniti alarm outputs.
Contact the factory if you have any questions or
comments.