MSA TG5000, Руководство по эксплуатации

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Maintenance
6.3 Clearing a Blockage
If using a Digital Sensor with Diffusion Supervision, and if the Diffusion Supervision feature has
been enabled in the Sensor Settings, the sensor will notify the user if it detects foreign material
obstructing the sintered metal frit where gas would normally enter the sensor (see Fig. 28). When
this condition is detected, the transmitter will go into fault and show “Diffusion Supervision Fault”
on the display. Follow these recommended steps to attempt to clear this fault:
(1) Inspect and clear the sensor inlet and frit.
(2) Inspect and clear any accessories attached to the sensor.
(3) Ensure Sensor is fully mated to the Sensor Body Assembly.
(4) Attempt to recalibrate the Sensor.
(5) Disable Diffusion Supervision or replace the Sensor.
First, with the sensor still installed, visually inspect the sensor to see if any objects are covering
the gas inlet and remove them. Example objects may include tape or the green Calibration Cap.
Next, check to make sure that there is no foreign material stuck to the frit. If any material is found
gently remove it while considering any hazards that may arise from such an action, like the accu-
mulation of a static charge and taking the necessary steps to avoid them. Take care to ensure
that the frit is not damaged during the cleaning process. DO NOT use water or liquids to try to
clean the frit. The frit acts like a sponge and will retain liquids, which will keep the gas path
blocked.
Fig. 28 Frit Location
If no material is visible, the frit may still be blocked by a liquid which has absorbed into the frit.
Once absorbed, liquids are very difficult to remove. For these situations, relying on natural evap-
oration is recommended. Due to the time it can take for liquids to evaporate sufficiently from the
frit, users may want to consider swapping out the affected sensor with one that is known to be
clear. Placing absorbent material against the outer surface of the frit can help accelerate this
process.
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