Det-Tronics U9500 Infiniti Gas Transmitter - Manual (Page 30)

95-8444 28 10.1
Table 14—Manual Calibration Procedure
Description Display Operator Action
Normal operation/no gas present Indicates the detected gas
concentration
• Ensure that the unit is set for Manual Calibration.
Refer to the “Setup Procedure.”
• If the possibility of background gases exists,
purge the sensor with clean air to ensure accurate
calibration.
Initiate calibration
Sequences through the Setup
settings
Enters the Calibration mode
-
Display shows detected gas
concentration and alternating
message:
“ZERO”
“CAL”
• Hold the Cal magnet to the CAL/RESET magnetic
switch for 7 seconds to enter the calibration mode.
(The external reset input can also be used to enter
the calibration mode if “EXT CAL YES” was selected
during the Setup procedure).
Zero calibration
Display continues showing detected
gas concentration and alternating
message:
“ZERO”
“CAL”
• When the zero reading has stabilized, hold the Cal
magnet to the CAL/RESET magnetic switch for 2
seconds to accept the displayed reading as the zero
point.
Apply calibration gas
Display shows detected gas
concentration and alternating
message:
“APLY”
“GAS”
• Apply the calibration gas to the sensor by placing
the calibration cup over the sensor and opening the
valve on the calibration gas cylinder.
Span calibration
Display shows rising gas
concentration and alternating
message:
“GAS”
“ON”
• When the reading has stabilized, hold the Cal magnet
to the CAL/RESET magnetic switch for 2 seconds
to accept the displayed reading as the span point.
The display will indicate the selected calibration gas
concentration as span.
Remove calibration gas
Display shows decreasing gas
concentration when gas is removed
and alternating message:
“CAL” “OK”
then
“RMV”
“GAS”
then
“XXXX SPAN”
• Remove the calibration gas. When the gas level
falls below the lowest alarm setpoint, the transmitter
automatically exits the Calibrate mode.
• A sensitivity reading that can be used to track sensor
life (except PointWatch) is displayed for 7 seconds
with the “SPAN” display and prior to the transmitter
returning to normal operation. Any reading over 100
indicates that the sensor is good.
• At the successful completion of the calibration, all
outputs and indicators return to normal operation.
• If faults are present, the unit will exit after the
remainder of 10 minutes. To force an exit from
calibration, make sure that the gas concentration is
below alarm setpoints and dropping, then activate
the CAL/RESET switch for 1 second.
Calibration fault indication
Display shows alternating messages
indicating the fault, then
“RMV”
“GAS”
• If a fault occurs, remove the gas and correct the fault.
After the fault has been cleared, begin calibration
again. See Table 15 - Fault Messages, Explanations
and Corrective Action.