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The PID sensor for this
MultiRAE PLUS
monitor is
constructed as a small cavity in front of the UV lamp. The
other sensors are mounted next to the PID sensor. A
diaphragm pump is installed inside the monitor to draw the
air sample into the sensor manifold and then distribute it to
all sensors.
A single chip microcomputer is used to control the
operation of the alarm buzzer, LED, pump and light sensor.
It measures the sensor readings and calculates the gas
concentrations based on calibration to known standard gases.
The data are stored in non-volatile memory so that they can
be sent to a PC for record keeping. RS-232 transceivers
provide a serial interface between the monitor and the serial
port of a PC. A 2-line by 16-character LCD display is used
to show the readings. The user interacts with the monitor
through three keys on the front panel keypad.
A rechargeable Li-ion or Ni-Cd battery or a set of four
disposable AA alkaline batteries powers the monitor.
NOTE: The printed circuit board is connected to the
battery pack even if the power is turned off. Therefore,
it is very important to disconnect the battery pack
before servicing or replacing sensors or any
components inside the monitor. Severe damage to the
printed circuit board may occur if the battery pack is
not disconnected before servicing the unit.
