Emerson MicroMotion HPC010 Installation Manual page 28

Purge the sensor case
March 2020
5. Make sure that there is a tight seal between the inlet connection and sensor case, so
6. Run purge gas through the sensor.
7. At the appropriate time, shut off the gas supply, then immediately seal the purge
8. Make sure that the purge fitting seals are tight so that air cannot be drawn by
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• If the purge gas is lighter than air (such as nitrogen), locate the inlet higher than
the outlet, so that the purge gas will displace air from top to bottom.
that air cannot be drawn by suction into the case or purge line during the purging
process.
The purge time is the amount of time required for full exchange of atmosphere to
inert gas. The larger the line size, the greater amount of time is required to purge
the case. If purge lines are being used, increase the purge time to fill the additional
volume of the purge line.
Important
Keep the purge gas pressure below 7.25 psi (0.5 bar).
outlet and inlet connections with the purge plugs.
Avoid pressurizing the sensor case. If pressure inside the case elevates above
atmospheric pressure during operation, the flowmeter density calibration will be
inaccurate.
suction into the sensor case.
Installation Manual
MMI- 20032352
Micro Motion HPC