Emerson Micro Motion Elite Coriolis Micro Motion Elite Coriolis CMF025 Installation Manual page 34

Supplementary information
3.
4.
5.
6.
30
Prepare the purge plugs for reinstallation by wrapping them with 2–3 turns of Teflon
tape.
Connect the supply of nitrogen or argon gas to the inlet purge connection or open
inlet purge line. Leave the outlet connection open.
• Exercise caution to avoid introducing dirt, moisture, rust, or other contaminants
into the sensor case.
• If the purge gas is heavier than air (such as argon), locate the inlet lower than the
outlet, so that the purge gas will displace air from bottom to top.
• 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.
Make sure that there is a tight seal between the inlet connection and sensor case, so
that air cannot be drawn by suction into the case or purge line during the purging
process.
Run purge gas through the sensor.
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.
Note
Keep the purge gas pressure below 0.5 bar (7 psi).
Table 5-1: Purge time
Sensor model
CMF010
CMF025
CMF050
CMF100
CMF200
CMF300
CMF350
CMF400
CMFHC2
CMFHC3
CMFHC4
CMFS007
CMFS010
CMFS015
CMFS025
CMFS040
3
Purge rate, in ft /hr (l/h)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
20 (566)
Time, in minutes
1
1
2
5
12
30
45
55
100
170
268
1 1/2
1 1/2
1 1/2
4 1/2
4 1/2
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