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Reference Manual
00809-0100-4444, Rev AC
Section 8: Maintenance
January 2015
Maintenance
8.6.2 Scaled D/A trim
A scaled D/A trim enables calibration of the flowmeter analog output using a different scale than
the standard 4-20mA output scale. Non-scaled D/A trimming (described above), is typically
performed using an ammeter where calibration values are entered in units of milliamperes.
Scaled D/A trimming enables trimming of the flowmeter using a scale that may be more
convenient based upon the method of measurement.
For example, it may be more convenient to make current measurements by direct voltage
readings across the loop resistor. If the loop resistor is 500 ohms, and calibration of the meter
will be done using voltage measurements across this resistor, the trim points can be rescaled
from 4-20mA to 4-20mA x 500 ohm or 2-10VDC. Once the scaled trim points have been entered
as 2 and 10, calibration of the flowmeter can be done by entering voltage measurements
directly from the voltmeter.
8.6.3 Digital trim
Digital trim is the function by which the factory calibrates the transmitter. This procedure is
rarely needed by users. It is only necessary if the Rosemount 8732EM is suspected to be no
longer accurate. A Rosemount 8714D Calibration Standard is required to complete a digital trim.
Attempting a digital trim without a Rosemount 8714D Calibration Standard may result in an
inaccurate transmitter or an error message. The digital trim must be performed with the coil
drive mode set to 5Hz and with a nominal sensor calibration number stored in the memory.
Note
Attempting a digital trim without a Rosemount 8714D Calibration Standard may result in an
inaccurate transmitter, or a “DIGITAL TRIM FAILURE” message may appear. If this message
occurs, no values were changed in the transmitter. Simply cycle power on the Rosemount
8732EM to clear the message.
To simulate a nominal sensor with the Rosemount 8714D Calibration Standard, change/verify
the following five parameters in the Rosemount 8732EM:
1. Calibration Number-1000015010000000
2. Units-ft/s
3. PV URV-20mA = 30.00 ft/s
4. PV LRV-4mA = 0 ft/s
5. Coil Drive Frequency-5Hz
LOI menu path
Diagnostics, Trims, Scaled D/A Trim
Traditional fast keys
1,2,5,2 or 1,4,2,1,7
Device dashboard 3,4,4,6
LOI menu path Device Setup, Diagnostics, Trims, Digital Trim
Traditional fast keys
1,2,5,3
Device dashboard 3,4,5