MAINTENANCE
7-6
5. Plug a new sensor into the empty sensor socket. Make
sure that black line on the sensor label is lined up with
the white marker on the PCB and the sensor pins are
aligned with the socket before pushing down the sensor.
6. Replace the gas piping plate and tighten the four screws
to hold down the sensors. Re-connect the battery pack.
Replace the monitor cover.
7. Turn on the power of the MultiRAE PLUS. The
microprocessor will automatically recognize the sensors
installed and configure the monitor accordingly.
Special Bias Voltage for Toxic Sensors:
The NO and NH
3
toxic sensors require a special 300 mV
bias voltage to operate. Only the Tox1 sensor position
provides such a special bias voltage. Therefore,
the NO or
NH
3
toxic sensor must be plugged into the Tox1 sensor
socket in MultiRAE PLUS
. In addition, there is a dip
switch or pin jumper located on the analog PCB next to the
PID sensor. When biased toxic sensor is plugged into the
Tox1 position, it is necessary to turn the dip switch or move
the jumper to the “ON” position to enable the bias voltage.
During power on sequence, the microprocessor will check
the sensor ID and the bias voltage. If the NO or NH
3
sensor
is plugged into the wrong toxic sensor socket or the bias
voltage is not switched on, an error message will be
displayed.
