Fluid Components International MT86_MT86HT Manual Troubleshooting - Manual (Page 10)

FLUID COMPONENTS INTL CHAPTER 5 - TROUBLESHOOTING
Models MT86, MT86HT 5 - 10 Doc. No. 003162 Rev. F
FC81 Field Calibrator Control Functions
The display shows the Delta "R" values or the output signal level depending on the position of the function switch.
The function switch, is a 2 position push-button switch, located on the left front panel of the FC81 field calibrator.
When the function switch is pressed to the in position the Delta "R" input resistance is displayed in ohms.
When the function switch is pressed to the out position the output signal is displayed in volts (0-10 Vdc).
Note: Follow the instructions on the front panel of the FC81 field calibrator to read the digital display.
Ohms Adjust
On the right side of the front panel is a 10-turn potentiometer that is used to input the desired Delta "R" resistance
values.
Add Ohms Switch
A Delta "R" value may be more than the maximum value of the ohms adjust potentiometer. If this happens, there is
another push-button switch on the right hand side of the panel that adds a fixed resistance to the displayed value.
If an MT86HT has a Delta "R" value greater than 10 ohms, use the add ohm switch.
If an MT86 has a Delta "R" value greater than 100 ohms, use the add ohm switch.
The display's readout does not show the ohms added. The ohms added MUST be added to the displayed resistance
for determination of the actual applied Delta "R". The ohms added and the displayed value MUST be combined to
get the actual Delta "R" value.
Connector Receptacle
On the rear panel of the field calibrator is an AMP brand receptacle with round post connectors for the test cable.
FC81 Field Calibrator Operating Procedure
1. This procedure adjusts the Delta "R" values to give a recorded output signal. Then Delta "R" value reading is
compared to the recorded value. This procedure verifies the proper operation of the flow transmitter. Be sure to
have the correct Delta "R" Data Sheet by checking the serial number of the flow element and the serial number
on the sheet.
2. Turn OFF the power to the flowmeter. Record where the jumpers are on the control board before the testing
begins. Remove the connector from the input board's terminal block TS1. Remove jumpers J2 and J8 if they
are present on the control board. If jumpers J1 and J3 are not installed, then install them at this time.
3. Connect the cable from the FC81 field calibrator to the input board terminal block TS1. Connect the ribbon
cable to any available output module connector; P7, P8, P9 or P11.
4. Turn the power ON and allow 5 minutes for the control circuits to stabilize.
5. Close switch SW1-3 that puts the flow transmitter in the manual mode; this enables the head-select switch SW2
to select and monitor one sensing point. Select the sensing point to be tested with the head-select switch, SW2.
6. With the FC81 field calibrator function switch in the out position, to readout the output signal, turn the ohms
adjust potentiometer to give a recorded voltage out.
7. Push the function switch in and read the Delta "R" (in ohms) that produced the recorded voltage out reading.
Record the measured signal.
8. Repeat Steps 6 and 7 for all values listed on the Delta "R" Data Sheet. The Delta "R" Data should repeat the
recorded value within 1.25% of full scale.
9. If all the measurements are within the limits, turn the power OFF and move the FC81 field calibrator to the next
sensing point to be verified. Repeat the procedure for the next sensing point to be verified. When the procedure
is finished, open switch SW1-3, and position the head-select switch SW2 to the number of sensing points in the
flowmeter.