Electronics Verification
March 2016
Reference Manual
00809-0100-4772, Rev FA
151
Electronics Verification
Note
On an MTA transmitter where the process fluid is set to TComp Saturated Steam, the
compensated mass flow uses a calculated density derived from the measured process
temperature. A flow simulation can be performed if the process temperature is at its normal
operating value. Conversely, if the temperature sensor is at a temperature grossly different
than the normal temperature, ambient for example, the calculated density and
compensated mass flow will be inaccurate. In such cases, change the process fluid to
gas/steam which will use a fixed process density value to simulate mass flow.
C.2.1 Electronics verification using internal flow simulation
In internal flow simulation mode, the flowmeter is capable of simulating either a fixed flow
rate or a varying ramped flow rate. The amplitude of the simulated signal is based on the
minimum required process density for the given line size and service type. Either fixed or
varying flow simulation will effectively disconnect the flow sensor from the electronics
charge amplifier input and replace it with the simulated signal. See Figure 7-2 on page 88.
C.2.2 Internal flow simulation—fixed flow rate
1. Set Simulation Control to Sim Internal Generator.
2. Select Simulation Units as either percent of range or engineering units.
3. Set the simulation Low Point and Simulation High Point to the same flow rate value.
C.2.3 Internal flow simulation—varying flow rate
1. Set Simulation Control to Sim Internal Generator.
2. Select Simulation Units as either percent of range or engineering units.
3. Set the Simulation Low Point. The simulation lowest flow rate.
4. Set the Simulation High Point. The simulation highest flow rate.
5. Set the Simulation Ramp Period. Entered in seconds.
The profile of the varying flow simulation signal is a sine wave that linearly increases and
decreases in frequency based on the ramp period. Figure C-9 illustrates how the flow is
varied.
Figure C-9. Profile of Varying Flow Simulation Signal
Max flow rate
Min flow rate
Ramp time
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