6
Model 850 Operation
Adjusting Sensitivity
• Rotate the
Sensitivity Adjust Control
knob clockwise until
meter just starts to deflect.
• Place the
Range
switch in the
“HI”
position.
• Place the
Purge
and
Mute
switches in the
down
position.
• The Model 850 is now ready for use and has a sensitivity of
approximately 50 parts per million (ppm) for methane as the
test gas.
ON/OFF &
Sensitivity
Adjust
Control
Mute
Switch
Purge
Switch
