High level rates, High level rates -7, Rosemount 3300 series – Emerson Guided Wave Radar Level and Interface Transmitters 3300 User Manual

Page 87

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Reference Manual

00809-0100-4811, Rev CA
February 2006

6-7

Rosemount 3300 Series

High Level Rates

The measurement signal is filtered in order to minimize the influence of
disturbing noise. In most measurement situations this does not have a
noticeable effect on the response time to level changes. If high level rates
occur it may however be necessary to reduce the damping value in order to
allow the transmitter to respond quicker. If there is too much noise the
damping value may be increased in order to get a stable measurement signal.

You can use the RCT software or a 375 Field Communicator to change the
Damping value. For the HART Communicator use the key sequence
[1, 3, 5].

In the RCT software open the Setup>Output tab and enter the desired
Damping value:

The Damping parameter determines how quickly the transmitter responds to
level changes and how robust the measurement signal is against noise.
Technically, a damping value of 10 means that in 10 seconds the output from
the transmitter is about 63% of the new level value. Consequently, when there
are rapid level changes in the tank, it may be necessary to decrease the
Damping value for the transmitter to be able to track the surface. On the other
hand, in noisy environments, and if level rates are low, it may be better to
increase the damping value to have a stable output signal.

Damping

Output tab

SETUP

_OUTPUT

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