7 zero reference – Meriam M2110F SMART FLOW GAUGE User Manual

Page 14

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6.4 Low Flow CutOff

1. Access P4: Low Flow CutOff
2. Sets a flow level for which the readout LCD and serial port devices will display a clamped measurement

value.

• For P4 >= 0.0 (Positive or Zero)

• If the measured flow value is below the Low Flow CutOff, the unit display will be forced to a zero

display value. The decimal point will flash to indicate an active Low Flow CutOff.

• For P4 < 0.0 (Negative)

• If the measured flow value is more negative than the Low Flow CutOff, the unit will display the

P4 value. The decimal point will flash to indicate an active Low Flow CutOff.

6.5 B Coefficient/Flow Constant

1. Access P9: B Coefficient/Flow Constant
2. Scales the primary element modeling equation / sets engineering units

• Input the proper setting of this register for both modeling types

3. Select the proper engineering units to match the scaling coefficients see Engineering Units below

6.6 C Coefficient

1. Access P10: C Coefficient
2. Input the proper setting of this register for P3=0 (Laminar Flow Element Modeling)
3. Return to measure mode and verify display for configured units


6.7 Zero Flow Reference

1. Zero the gauge with zero flow through the primary element
2. Press the UP AND DOWN ARROW KEYS simultaneously
3. If lockout is in-active display will flash 0000 during zero sampling

• Gauge returns to MEASURE MODE

4. If lockout is active prompt will be L 00

• Enter Lockout Code

• Display will flash 0000 during zero sampling

5. Setpoints might be active(See page 12 for details)

7 ZERO REFERENCE

The gauge zeroing process requires that a flow generating less than 5% of the differential pressure sensors full-scale
range be present. This differential pressure generated from the primary element as the zero reference will be
measured by the pressure sensor and used as a zero reference for all future flow calculations. Prior to zeroing the
gauge all flow should be cut off to the primary element used as the differential pressure source for the gauge sensors.


7.1 AFFECT ON OUTPUTS

The SetPoint and Current Loop outputs are calculated based on the displayed flow. Since re-zeroing the gauge may
change the calculated flow, these outputs may be affected by the zeroing procedure. For safety purposes the process
should be in a zero flow condition with static pressure when the zeroing is initiated. After the zeroing the threshold
settings for the relay or current loop outputs should be checked for proper operation.

7.1.1

RE-ZEROING THE GAUGE / OUTPUTS DISABLED (P5=0):

1. Gauge in MEASURE MODE with zero flow through primary element
2. Press the UP AND DOWN ARROW KEYS simultaneously
3. If lockout is in-active display will flash 0000 during zero sampling

• Gauge returns to MEASURE MODE

4. If lockout is active prompt will be L 00

• Enter Lockout Code

• Display will flash 0000 during zero sampling

• Gauge returns to MEASURE MODE

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