Safety Instructions; Delta R Check; Figure 53 - Dmm Hookup To Measure 4-20 Ma Output - FCI MT100 Installation, Operation And Maintenance Manual

MT100 Multipoint Flow Meter
Each flow meter is provided with a Delta R data sheet which is a table listing the differential resistance values that correlate to the flow
meter's calibration. Resistance substitution instruments like the FES-200 can be used to check instrument calibration and verify correct
operation of the flow transmitter using the Delta R data sheet.
To verify the transmitter is working properly, the sensor head must be disconnected and precision resistance (Delta R) values from the
FES-200 are substituted. Then by measuring the transmitter output and display it can be determined whether the transmitter is still within
factory specification.

Safety Instructions

Warning:

Delta R Check

1. Verify the Delta R data sheet has the same serial number and group number as the flow meter calibration that is being verified.
2. Turn transmitter power OFF.
3. Disconnect a flow element sensor from the MT100 transmitter (TBx) and connect the FES-200 cable connector in its place. See
Figure 54. Precision decade boxes can be used in place of the FES-200. See
4. Connect a DMM to the transmitter 4-20 mA output by either method A or B as shown in Figure 53 below.
a. To read 1 to 5 volts, disconnect both output loop wires and connect a precision 250 Ω resistor across the output terminal. Then
connect the DMM, set to DC volts (V), across the resistor to read its voltage drop.
b. To read 4 to 20 mA current, disconnect the output loop and connect the DMM, set to milliamps (mA), in series with the output
circuit to read the current flow.
5. Turn transmitter power ON and allow the instrument 10 minutes to stabilize.
6. Verify the transmitter is in the calibration group matching the Delta R data sheet.
7. On the FES-200, dial in a Delta R value with the thumbwheel from the column marked Delta R (ohms) on the Delta R data sheet. Compare to
the output value column (VDC Across 250 Ohms or mA Output as applicable) and/or the Indicated Display column. Verify that the meter
reading is within the stated tolerance of the flow transmitter. See examples 1, 2 and 3 at the end of this section, as applicable.
8. Repeat for each point on the Delta R table, except for the step value and zero value.
9. Turn power OFF and disconnect the FES-200 and DMM. Reconnect the sensor element connector.
10. Close the enclosure, making sure none of the wires are strained. Ensure any seals and gaskets are properly installed.
11. Restore power to the meter.
If you are troubleshooting the flow meter and the readings are good, the flow transmitter is good and the problem may involve the flow
element or interconnecting cable. If the readings are off, a flow element calibration may be required or the flow transmitter needs to be
setup. Contact FCI Customer Service.
Fluid Components International LLC
Explosion Hazard. Do not disconnect equipment when flammable or combustible atmosphere is present. Operator
assumes responsibility for all safety concerns relating to interrupting and reapplying power to their instrumentation.
Figure 53 – DMM Hookup to Measure 4-20 mA Output
TROUBLESHOOTING
Figure 55 for decade box wiring.
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