Emerson Rosemount 8600 Series - D;A Trim(Digital-To-Analog Trim); Scaled D;A Trim

Reference Manual
00809-0100-4860, Rev BF
Operation
May 2019
48
Rosemount 8600 Vortex Flow Meter
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
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(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
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. Once your scaled trim points have been entered as 2 and 10, you can now
calibrate your flowmeter by entering voltage measurements directly from the voltmeter.
FastKeys
1, 2, 4, 4
FastKeys
1, 2, 4, 5
FastKeys
1, 2, 5
FastKeys
1, 2, 6