Emerson 2200S User Manual

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This chapter contains information and procedures that may be useful for testing the flowmeter before 
moving it into production. The following topics are discussed:

•

Zeroing the flowmeter – see Section 7.2

•

Loop testing – see Section 7.3

•

Trimming the mA output – see Section 7.4

•

Using sensor simulation to test the system – see Section 7.5

•

Backing up the configuration – see Section 7.6

•

Write-protecting the configuration – see Section 7.7

Before performing any of the procedures in this chapter, make an administrative connection to the 
transmitter and ensure that you are complying with all applicable safety requirements.

Zeroing the flowmeter establishes the flowmeter’s point of reference when there is no flow. The meter 
was zeroed at the factory, and should not require a field zero. However, you may wish to perform a 
field zero to meet local requirements or to confirm the factory zero. 

When you zero the flowmeter, you may need to adjust the zero time parameter. Zero time is the 
amount of time the transmitter takes to determine its zero-flow reference point. The default zero time 
is 20 seconds.

•

A long zero time may produce a more accurate zero reference but is more likely to result in a 
zero failure. This is due to the increased possibility of noisy flow, which causes incorrect 
calibration.

•

A short zero time is less likely to result in a zero failure but may produce a less accurate zero 
reference.

For most applications, the default zero time is appropriate.

Note: Do not zero the flowmeter if a high-severity alarm is active. Correct the problem, then zero the 
flowmeter. You may zero the flowmeter if a low-severity alarm is active. See Section 8.6 for 
information on viewing transmitter status and alarms.

If the zero procedure fails, two recovery functions are provided:

•

Restore Prior Zero

•

Restore Factory Zero