Omega PRESSURE GAUGES DPG3000 - Manual (Page 2)

DPG3000 Digital Pressure Gauge instructions
All units are factory calibrated prior to shipment.
1) ZERO TRIMMING:
Loosen the set screw retaining the front cover and rotate counter-
clockwise to remove. You will now have access to the zero adjust
potentiometer which is marked with a “Z”. An ideal zero is indicated
by a reading of 000 with an intermittently flashing “-” sign.
A jeweler screwdriver or an eyeglass screwdriver is a suitable
instrument. Be careful NOT to touch the “S” pot to the right, as
changing this adjustment will invalidate the factory calibration.
2) BATTERY REPLACEMENT:
After removing the front cover as in 1), loosen the small set screw at the
bottom of the Display Assembly and remove the Assembly from the
Housing (be careful of the Sensor Leads). The batteries can now be
pulled from the holders and replaced with P/N DPG-BAT-C or equivalent.
3) RE-CALIBRATION
This procedure requires a known pressure source of at least +/-0.1%
accuracy in order to fully utilize the accuracy potential of the DPG-3000.
(If not available, gauge can be returned for re-calibration).
4) PROCEDURE:
A) With 0 psig applied (port vented) adjust zero as per instructions in #1.
B) Apply full-scale pressure to the pressure port and adjust the span
(“S”) pot until display reads the correct pressure.
C) Re-check zero and re-adjust the zero (“Z”) pot if required.
D) Repeat steps B) and C) until no further adjustment is required.
5) 4/20 mA TRANSMITTER OPTION: (–A4 Option)
When equipped with this option the gauge no longer operates from batteries
but instead is “Loop Powered”. The loop connection is made to a
terminal strip located inside the housing. A voltage of between 9 and 32
VDC must be maintained at this connection (Red is positive “+” black is
negative “-”) to insure proper operation. Completion of the earth or
system ground (Green) is recommended for proper circuit protection.
Power supply voltage must be sufficient to maintain a minimum of 9 VDC
at the gauge terminals after “dropping” voltage across RL at full scale
current (20mA). Example: If RL = 250 ohm then “drop” is 0.02 Amps X
250 ohm = 5 volts. Therefore power supply minimum is 5V + 9V = 14V.
RE-CALIBRATION: Procedure is the same as in 3,except that there are 2 sets of
zero and span adjustments. The front panel controls affect the display and
the rear controls (remove electronics as in Step 2) affect the 4/20 mA signal.
NOTE:
DO NOT UNSCREW SENSOR FROM HOUSING, THIS WILL DAMAGE THE UNIT.
R
L
Green
Red
Black
Earth or
System Ground
Voltage
Output
+
+
–
–
D.C. Power
Supply
LOBAT
Kg/Cm 2
Z S