4½ Digit loop-powereD meters
www.predig.com
Precision Digital corPoration
89 October Hill Rd • Holliston MA 01746 USA • Tel (800) 343-1001 • Fax (508) 655-8990
LDS675_A 09/11
WARNING:
If any of the following operations are performed in
hazardous areas, all appropriate hazardous area procedures must
be followed.
WARNING:
Disconnect from supply before opening.
WARNING:
Calibration of the Loop-Powered Display should
be performed in a non-hazardous area prior to installing it in its
enclosure.
CAUTION:
Care should be taken to avoid static electricity
damaging the electronic circuitry.
setUp
The only tools needed for calibration are a calibrated current
source, a flat head screwdriver & a phillips head screwdriver.
Please note that the meter must be disassembled in order to
perform the setup functions.
Disassembly
The calibration controls are located behind the display faceplate.
To access these controls, you must first remove the enclosure
cover and faceplate by doing the following:
Loosen the four screws on the enclosure cover and remove.
Unscrew the two fasteners that hold the faceplate, then remove.
Connections
Field connections are made to the screw terminals located on
the Signal Input Board. To access these screw terminals it is
necessary to remove the Display Board from the Signal Input
Board. First, disconnect the ribbon cable connector from the
Display Board. Next, remove the two screws located to the left
and right of the LCD that hold the Display Board in place. Finally,
remove the Display Board carefully to avoid contact with any
rough surfaces.
J1
Input
4-20 mA
Transmitter
Loop Power
Supply
+ –
Figure 2. signal input Connections
Calibration Controls
Calibration of these meters is a two-step process involving four
controls. These controls are located on the Display Board. The
LO controls are on the right and the HI controls on the left. The
pre-configured jumper array JP2 and JP3 are also located on the
Display Board.
Calibration procedure
Connect the 4-20 mA input signal. Apply 4 mA to the input and
adjust the coarse and fine LO controls for the desired reading.
Next apply a signal between 16 and 20 mA and adjust the
coarse and fine HI controls for the desired reading. Complete the
calibration by making any minor adjustments to the LO and HI
displays.
Jumper positions
JP2
JP3
JP1
1
2
3
4
Cable
1999.9
F-HI-C
C-LO-F
R24
Figure 3. Display Board
Balance Potentiometer (R24) is preset at the factory
Decimal point selection
Decimal point selection is accomplished using JP1 located behind
the faceplate to the right of the display. Leave jumper on one pin
only for a display of 19999 (default), place the jumper over both
pins of #1 for a display of 1999.9, #2 for 199.99, #3 for 19.999,
#4 for 1.9999
JP1
1
2
3
4
Disclaimer
The information contained in this document is subject to change without notice. Precision Digital
Corporation makes no representations or warranties with respect to the contents hereof, and specifically
disclaims any implied warranties of merchantability or fitness for a particular purpose.
© 2008-2011 Precision Digital Corporation. All rights reserved.
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