MUNI User’s Guide
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8. Maintenance
The MUNI requires little maintenance, aside from daily battery charging (see Section 2), regular
filter replacement, and sensor replacement as needed (1 to 3 years depending on sensor and use
conditions). The battery may need replacement after long service or extreme use conditions.
8.1 External Filter
Use an external filter in environments with excessive dust or liquid aerosols. The filter attaches
to the front housing covering all four sensor gas inlet ports.
NOTE:
The external filter will slow the response of the MUNI sensors. Replace the filter when
it is visibly dirty or when response times become noticeably long.
8.2 Replacing Internal Filter, Sensors, LCD or Battery
WARNING!
Open the instrument housing only in non-hazardous locations.
1.
Turn off the instrument.
2.
Remove the six screws in the back of the instrument.
3.
Turn the instrument over, lift off the front cover.
4.
Sensors
: Carefully lift out each sensor to be inspected or replaced.
Install the replacement sensor. Make sure the electrical contact pins are aligned with the
holes in the PC board and that the sensor is seated firmly. Sensor locations are marked on the
circuit board and sensors cannot be exchanged with different types.
5.
Filter
: On the inside of the front housing cover, peel back and replace the white filter pad
and/or the black sensor gasket, as needed.
6.
LCD
: Lift out the LCD and place the electrical ribbon of a new LCD onto the small white
connector on the circuit board. Push down the black clamp to secure the ribbon (see below).
7.
Battery
: The battery is soldered onto the bottom of the circuit board and should be replaced
at an authorized service center.
8.
Ensure that the LCD is connected, replace the housing cover, and tighten the 6 screws.
IMPORTANT!
Always perform a full calibration after replacing sensors.
Sensor & LCD
replacement
Filter & gasket
replacement
LCD connection:
a. Place LCD ribbon flat onto white bracket
b. Push black clamp onto ribbon to secure
