AW Gear Meters EMO-3000 - Manual (Page 18)

EMO‐3000
Operation and Programming Manual
17
Linearizer Operation
The EMO‐3000 features a fully programmable 10‐point linearizer. The linearizer corrects for errors over
the flow transmitter’s indicating range using the calibration data. The linearizer can only be used if there
is an accurate calibration for that particular flow meter in the range required. The linearizer can be used
in any operating mode: Monitor, PID, or Ratio. The corrections can be based on either the frequency
input A or B, or both A and B.
In the programming screen of the DM‐3000, if you select 3 = LINEARIZER, you can program the 10 error
points and their associated error percentages. The linearizer can then be “turned on” and directed to
the correct input under the GENERAL A variables. The rule for operation is:
LINEARIZER = 0 OFF
LINEARIZER = 1 FREQUENCY INPUT A
LINEARIZER = 2 FREQUENCY INPUT B
LINEARIZER = 3 BOTH A and B INPUTS
In most cases, it is not necessary to program the linearizer. If you are using a Positive Displacement flow
meter for the right application, errors are usually less than .5% and are therefore negligible: if the
linearizer is programmed to correct for less than 1%, there is little chance of improving system
performance.
Turbine flow meters are often where the linearizer is most effective. The reason is that often a turbine
flow meter reacts to differences in fluid speeds over a given range in a non‐linear fashion. If an accurate
calibration sheet is available showing the percent of deviation, you can program the 10‐point linearizer
to correct the fluid flow rates the EMO‐3000 indicates. For instance, if the calibration data for a
particular flow meter are:
Frequency: HZ Rate: GPM K‐Factor (Imp/Gal) Error %
10 .26 2037.7 ‐5.2
100 2.6 2157.7 +0.5
500 13.00 2100.0 ‐2.5
If the percentage of error is not in the calibration data, calculate it using the average k‐factor.
Notice
Notice