Det-Tronics UD10 FlexVu Explosion-Proof Universal Display Unit - Manual (Page 15)

13 95-8661 4.2
4-20 mA lOOp CAlIBRATION
Both the input and output current loops of the UD10
are trimmed at the factory. They can also be trimmed
in the field for maximum accuracy using the following
procedures. If the detector connected to the UD10 is
HART enabled, its 4-20 mA output signal can also be
trimmed.
When the UD10 is used with a detector that supports
HART communication, the output of the detector should
be calibrated first.
HART Detector Signal Calibration
Navigate down the menu to Device Test > D/A (Digital
to Analog) Trim.
Main Menu
Process Vars
Display Status
Device Status
Display Setup
Device Setup
Device Cal
Display Test
Device Test
Device Test
Self Test
Response Test
Loop Test
D/A Trim D/A Trim
Zero Trim
Gain Trim
Select Zero Trim. When this screen is entered, a
warning message is presented. Select ENTER to
continue. When the message “Connect Reference
Meter” is presented, install the current meter on the mA
line between the detector and UD10. Select ENTER
to continue. When the message “Set Input Current to
4mA?” is presented, select ENTER to begin the Zero
Trim function. The detector will now set its 4 mA output
value. If the value indicated on the current meter is not
4.00 mA, enter the measured value into the UD10 using
the Previous and Next switches. The UD10 calculates
and corrects for the difference between the actual and
entered values. When the current meter value is at the
desired 4.00 mA, select ENTER to accept the new zero
trim value.
Select Gain Trim. Follow the same procedure for gain/
span calibration.
UD10 Input Trim
When the UD10 is used with a detector that supports
HART communication, an automated process can be
used to trim the UD10 input. Navigate down the menu
to “Input Loop Cal”.
Main Menu
Process Vars
Display Status
Device Status
Display Setup
Device Setup
Device Cal
Display Test
Device Test
Display Setup
Alarm Setting
Mode Select
HART Option
RTC
RS485
Input Loop Cal
Upon entering Input Loop Cal, the UD10 commands
the detector to output 4 mA, and then automatically
calibrates its own input. The UD10 then commands the
detector to output 20 mA and subsequently calibrates
its own input.
If a non-HART detector is being used, the Input Loop
Cal may be performed with a mA current source or loop
calibrator connected to the UD10 Sensor Connector.
Follow the loop calibration instructions shown by the
UD10 for this procedure.