TROUBLESHOOTING
8 - 4
1) Raw Sensor Readings
The raw sensor readings provide a quick diagnosis on the
baseline and sensitivity of each sensor. When zero gas
(fresh clean air) is applied to the monitor, the raw sensor
readings typically should be between 100 to 300 for toxic
sensors, between 1800 to 2600 for LEL or VOL sensor and
between 800 to 1200 for oxygen sensor. If the raw reading
is outside these ranges when zero gas is applied, the sensor
or the electronics may be defective.
When a specific gas is applied to the monitor, the
corresponding sensor should respond and the raw reading
should increase or decrease. If the reading of the
corresponding sensor does not change when the specific gas
is applied, then the sensor may be defective.
165
160
173
2051 RAW 1079
2) Sensor Name
All the toxic, oxygen and LEL sensors have a non-volatile
memory which contains the sensor identification and other
vital information, such as manufacturing date, expected
operating life, etc. If a sensor is programmed and installed
properly in the monitor, the sensor name should be
displayed. If the sensor name does not show up in the
display, then the sensor may not be programmed properly or
may be defective.
3) Battery Type and Battery Temperature
The VRAE monitor can be powered by either a rechargeable
NiMH, Ni-CD battery pack or an alkaline battery adapter.
The microprocessor automatically detects the type of
