VEGA D77 Hydrostatic pressure transmitters - Manual (Page 18)

18 Pressure transmitters D76 and D77
1
2
3
4...20mA
12...36 V DC
+ -
S
Z ti
Op
- +
1 2 3 4 5
Setup
5 Setup
5.1 Sensor without adjustment
Sensors with electronics version A and C
have no adjustment possibility and are per-
manently adjusted to the stated measuring
range.
5.2 Adjustment with the adjustment
insert in the sensor
Sensors with electronics version D are
equipped with a 2-key adjustment insert.
Procedure
• Select the required function with the rotary
switch.
• With the "+“ and "–“ key you modify the
signal current to the required values or set
the suitable integration time.
• Then, you set the rotary switch to position
"OPERATE“. The set values are transferred
to the EEPROM memory and remain there
even in case of voltage failure.
Adjustment
For adjustment of zero and span, first of all
connect terminals 1 and 3 to an ammeter. The
measured value is identical to the output
current.
First of all adjust zero (empty vessel)
• Set the rotary switch to "zero“. Empty the
vessel.
• Adjust a current of 4 mA by pushing the "+“
and "–“ keys.
The adjustment range of zero can be be-
tween -20 % and +95 % of the nominal meas-
uring range.
Then adjust span (full vessel)
• Set the rotary switch to "span“. Completely
fill the vessel.
• Adjust a current of 20 mA by pushing the
"+“ and "–“ keys.
The adjustment range of span can be be-
tween 3.3 % and 120 % of the nominal meas-
uring range.
1 Reduce value
2 Rotary switch
3 Increase value
With the rotary switch you can select four
switch positions:
S
- Span (pressure measuring range)
Z - Zero (zero adjustment)
ti - Time (integration time)
O p - Operate (operating status)