MSA PrimaX IR+ Operating Manual page 34

6 Maintenance
Figure 22 Light Path Obscuration
WARNING!
The sensor will not respond to the presence of gas in cleaning mode.
Ensure that the environment is free of combustible gases before starting the cleaning procedure.
Failure to follow this warning can result in serious personal injury or death.
• The analogue current output will be set to the Cleaning Mode value (→
Sequence) during this time.
• If monitoring the HART signal, the Cleaning Status bit will be set.
Although both windows are made of a highly durable material that is not easily scratched, avoid excessive pressure
when cleaning them. Clean, cotton tipped applicators are recommended to remove material collected on the windows.
3. Use a dry applicator or one moistened with distilled water to wipe the window and remove dust.
4. Use an additional clean, dry applicator to remove any residual water.
5. Use an applicator moistened with isopropyl alcohol to remove heavy deposits of solids, liquids or oil films. Clean
the window again with a second applicator moistened with distilled water; then, dry the window with a final
applicator.
6. Avoid using excessive amounts of water or alcohol in the cleaning procedure, and inspect the window to ensure
that the entire surface is clean.
NOTE: When the cleaning process is complete, be sure to remove all objects from the light path.
When exiting the Cleaning Mode, the unit returns to normal operation. Note that residual cleaning fluids may result in an
elevated signal until completely dry.
7. Inspect the environmental guard for any blockages, then replace the environmental guard on sensor.
○ After cleaning the windows, it is advisable to check the sensor's response to both zero and calibration gas.
NOTE: If water or isopropyl alcohol is used to clean the sensor's windows, any residue from the cleaning procedure
must be completely dissipated before returning the unit to service. Checking the sensor's response to zero gas is the
best way to purge residual cleaning materials from the sensor. Ensure that the sensor's reading is stable before zeroing
or calibrating the sensor (→
34
5.2 PrimaX IR+ Calibration). Failure to do so could result in inaccurate readings.
2. Place an opaque object (piece of paper, two fingers,
etc.) between the light source window and the mirror to
completely obscure the light path for two to three
seconds (→ Figure 22
○ If the opaque object is left in the light path for
longer than 10 seconds, an Obscuration fault
will be set on the mA output (→
Controller and Menu
○ The device enters the Cleaning Mode for 5
minutes.
5.1 Remote Controller and Menu
).
5.1 Remote
Sequence).
US