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Chapter 3 Operation Series 780S Instruction Manual
3-14 IM-78S-B
Electronics Validation Procedure
1. Verify the flow meter is off line from any remote communica-
tions. Make sure the meter’s user full scale setting is the same as
the factory full scale setting. If not, adjust the user full scale
value as needed.
2. Locate the Calibration Certificate supplied with the flow meter.
Record in Table 3-1 the five bridge voltage values, the output
(VDC or mA) values and the indicated flow values.
3. Remove power from the flow meter. Remove the cover(s) of the
flow meter enclosure to access the wiring terminal block and the
Smart electronics device.
4. Set the multimeter to the 20 volt range. Connect to BV(+) and
BV(–) terminals on the flow meter terminal block.
5. Move the J1 Cal/Run jumper on the Smart electronics device to
the CAL position. Locate potentiometer VR3 on the Smart elec-
tronics device. Turn on power to the flow meter.
6. Adjust potentiometer VR3 until the multimeter matches the first
bridge voltage point (the value must be ± 0.002 VDC of the
bridge voltage point).
7. Record the resulting flow shown on the optional LCD display in
Table 3-1. If not using a display or if you prefer to validate one
of the analog output signals, move the multimeter + connection
to Vout (+). Record the resulting output voltage in Table 3-1. If
using a 4-20 mA calibrated meter, set the multimeter to read cur-
rent and connect the meter to read the mA signal in your con-
nected loop. Record the resulting current output in Table 3-1.
8. Repeat Step 6 and Step 7 to record the results of the remaining
four bridge voltage validation points in Table 1. Compare the val-
ues recorded in Table 3-1. Indicated values must be within the
flow meter’s stated accuracy shown on the Calibration Certificate.
9. When data collection is complete, turn off power to the flow me-
ter. Disconnect the multimeter from the flow meter terminal block.
10. Place the J1 Cal/Run jumper in the RUN position. Make sure the
jumper is securely in place before resuming flow meter opera-
tion. Replace the flow meter cover(s).
Caution!
Before beginning this
procedure, make sure the
flow meter is not actively
monitoring or reporting to
any master control sys-
tem. Any adjustment to
the electronics will cause
direct changes to flow
control settings.