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Reference Manual
00809-0100-4860, Rev BC
Section 4: Operation
January 2013
Operation
Simulate flow external
Simulate flow external allows you to disconnect the sensor electronically so an external
frequency source can be used to test and verify the electronics.
Enable normal flow
Enable normal flow allows you to exit the flow simulation mode (internal or external) and return
to normal operation mode. Enabled Normal Flow must be activated after any simulation is run.
Failure to enable normal flow will leave the Vortex in simulation mode.
Mode
Mode allows you to view which flow simulation mode you are in:
Internal (flow simulation – internal)
Snsr Offln (flow simulation – external)
Norm Flow (normal flow operation)
4.1.5 D/A trim
D/A Trim (Digital-to-Analog Trim) enables you to check and trim the analog output in a single
function. If the analog output is trimmed, it will be scaled proportionally through the range of
the output.
To trim the digital-to-analog output, initiate the D/A Trim function and connect an ammeter to
the loop to measure the actual analog output of the meter. Follow the on-screen functions to
complete the task.
4.1.6 Scaled D/A trim
Scaled D/A Trim enables you to calibrate the flowmeter analog output using a different scale
than the standard 4-20 mA output scale. Non-scaled D/A Trimming (described above), is
typically performed using an ammeter where calibration values are entered in units of
milliamperes. Both non-scaled D/A trimming and scaled D/A trimming allow you to trim the
4-20mA output to approximately ±5% of the nominal 4mA end point and ±3% of the nominal
20mA end point. Scaled D/A Trimming allows you to trim the flowmeter using a scale that may
be more convenient based upon your method of measurement.
For example, it may be more convenient for you to make current measurements by direct
voltage readings across the loop resistor. If your loop resistor is 500 Ohms, and you want to
calibrate the meter using voltage measurements made across this resistor, you could rescale
(select CHANGE on the 375) your trim points from 4-20 mA to 4-20 mA x 500 ohm or 2-10 Vdc.
Field Comm. 1, 2, 4, 3, 2
Field Comm. 1, 2, 4, 4
Field Comm. 1, 2, 4, 5
Field Comm. 1, 2, 5
Field Comm. 1, 2, 6