Initial Bridge Sensor Monitor Start-Up - Oldham OLCT 200 User Manual

3.1.3 Model Name
When power is applied to the OLCT 200 it will briefly show a 10 digit ASCII model
name or company name as it starts up. The name can be edited in the Transmitter
Configuration menu by editing the Model field.

3.2 Initial Bridge Sensor Monitor Start-Up

OLCT 200 LEL Monitors that are factory equipped with Smart Bridge sensors rarely
require adjustments, other than routine calibrations, to provide accurate LEL readings.
However, after installation the following checks should be performed to insure proper
operation. In addition, alarm levels, Measurement Name ASCII fields and other
variables may require configuration by users in order to best serve their application.
Initial Bridge Sensor Monitor "Sensor Volts" Check
3.2.1
CAUTION: Sensor Volts in excess of the rated values may destroy catalytic bead
sensors. OLCT 200 sensors are rated for 2 volts.
Section 6.2 describes reading and setting "sensor volts" using the OLCT 200 LCD.
The voltage displayed on the LCD is monitored across TB1-REF and TB1-ACT on the
OLCT 200 Power Supply board (Figure 2.4) and may be confirmed with a voltmeter.
This TB-1 value is correct for locally mounted sensors only. Sensors mounted more
than a few feet away from the OLCT 200 may receive a lower voltage due to the
inherent voltage drop across sensor wiring. Remote mounted sensors must have their
sensor voltage (across ACTIVE and REFERENCE beads) measured AT THE
SENSOR end of the cable. The OLCT 200 setting will require a higher value in order
to achieve the correct voltage at the sensor. Correct sensor voltage should be
confirmed after start-up for locally and remotely mounted catalytic bead sensors.
Initial Bridge Sensor Monitor "Balance" Check
3.2.2
Catalytic bead sensors connect to a bridge circuit that may require a balance
adjustment after installation especially when the sensor is remote mounted from the
OLCT 200. Section 7.2 describes using the LCD to read and adjust BALANCE
settings. Correct BALANCE setting should be confirmed after start-up for locally and
remotely mounted catalytic bead sensors.
Figure 3-2: Output ZERO / SPAN Trim Menus
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