EN.IO.AS.dP
8
Revision 01.A.001/2021.11
7. POWER SUPPLY
Table 3
. Transmitter supply voltage.
8…39 V DC
Output signal
4…20 mA
2 wires
13…30 V DC
Output signal
0…10 V DC
3 wires
where:
U
sup
-
voltage at the supply terminals of the 4…20 mA current loop [V].
U
min
- minimum supply voltage of transmitter
R
Lmax
- maximum power supply line resistance
[Ω].
8. OPERATION
Protect the transmitter against mechanical damage and flooding.
Do not allow any sludge to form on the membrane. Carry out regular inspections.
Temperature range of measuring medium:
•
-
25 ÷ 120ºC – direct measurement;
•
> 120
ºC - measurement using a pulse tube, e.g. for media with a temperature of 160ºC the
length of the im-pulse tube should be at least 150 mm.
Isolation test voltage 110 V DC.
8.1.
Setting of measurement range width and zero point
Unscrew the electrical connection to access the potentiometer knobs. Connect and power the transmit-
ter according to the technical data. Apply a pressure equal to the lower limit of the measuring range
and bring the output signal to 4 mA (0 V) by turning the "zero" potentiometer knob (turning it clockwise
increases the output signal). After zeroing, set the pressure equal to the upper range limit and use the
"range" potentiometer to bring the output current (voltage) to 20 mA (10 V). Check "zero" again and
repeat the setting if necessary.
Attention:
The user, by means of potentiometers, has the possibility to adjust the "zero" and the range within the
limits up to ±10%.
For transmitters with output signal 0...10 V the "zero" should be set to 0.05 V (transmitters do not reach
0 V).
9. MAINTENANCE
9.1.
Periodic inspections
Periodic inspections should be carried out in accordance with the standards binding for the user. During
the inspection it is necessary to check the condition of pressure connections (absence of loosening and
leakage) and electrical connections (checking the reliability of connections and the condition of seals
and glands).
9.2.
Cleaning, washing
In order to remove dirt from the external surfaces of the transmitter, wipe them with In order to remove
dirt from the external surfaces of the transmitter, they should be wiped with a cloth dampened in water.