accuracy). The controller calibration procedure
can then be used for all subsequent calibrations.
Setting Controller Default Values
(Required for Transmitter Calibration)
IMPORTANT
This procedure must be performed in addition to
transmitter calibration.
The controller must be set for the factory default cali-
bration values as follows:
1. Press and hold the RESET button for approxi-
mately 9 seconds until the digital display begins
flashing and the CAL LED is illuminated. Release
the RESET button.
2. Press the SET button. The FAULT LED comes on.
3. Press the RESET button. The controller returns to
the normal operating mode after a time delay (up
to five minutes).
4. The controller is now set for the factory default
values. The above procedure does not need to
be performed with each recalibration unless a
controller calibration (described below) is per-
formed.
Calibrate the sensor/transmitter using the procedure
recommended in the appropriate sensor/transmitter
manual.
Transmitter Calibration Procedure (K Series)
The K Series Transmitter can be calibrated using
either of two procedures. The standard calibration
procedure can be performed by one person using the
plug-in calibration meter. In addition to calibrating
the sensor, this procedure tests sensor sensitivity.
The alternate calibration procedure uses the digital
display on the controller instead of the plug-in calibra-
tion meter to indicate sensor response. In most appli-
cations, two people are needed to perform this cali-
bration. No sensor sensitivity test is possible.
For information regarding calibration of other transmit-
ter models, refer to the appropiate instruction manual.
1. Verify that the area is safe for entry (no dangerous
levels of either toxic or combustible gas are pre-
sent).
CAUTION
A portable instrument should be used to ensure
that the area is clear of any combustible gases.
If there is any indication of the presence of com-
bustible gas at the sensor, calibration or mainte-
nance should not be performed.
The location must be de-classified prior to cali-
bration.
2. Remove the junction box cover and plug the cali-
bration meter into the socket on the transmitter.
3. Adjust the Zero control with a screwdriver until the
meter displays 0% LFL (Figure 14). If the possi-
bility of background gases exists, purge the sen-
sor with clean air to assure accurate calibration.
NOTE
If a dust cover or splash shield is used, it should
be checked to ensure that it is not dirty or
plugged. A plugged dust cover can restrict the
flow of gas to the sensing element, seriously
reducing its effectiveness. For optimum perfor-
mance, sensor covers/filters should be replaced
at each calibration to ensure that they have not
been degraded or plugged.
4. Apply the calibration gas to the sensor. (Be sure
that the pressure gauge indicates that there is
enough gas in the tank to complete the calibra-
tion.)
5. When the display shows a stable reading, adjust
the Span control until the meter displays the same
% LFL as indicated on the calibration tank (typi-
cally 50%).
6. Press the sensitivity check button. If the display
reads less than 15, check the sensor voltage (it
should measure 3.3 vdc). If the sensor voltage is
correct, sensor replacement is recommended. If
the sensor must be replaced, refer to the “Sensor
Replacement” section.
7. Remove the calibration gas from the sensor. DO
NOT REMOVE THE CALIBRATION METER until
the reading on the calibration meter returns below
the low alarm setpoint level (or 5% LFL), or an
alarm will be generated by the controller.
8. Unplug the calibration meter and replace the
junction box cover.
Alternate Calibration Procedure for K Series
Transmitters
This method of calibrating the K Series Transmitter
uses the digital display on the controller for indicating
sensor output, eliminating the need for the plug-in cal-
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