NT® PRESS URE T RANSDUCER USER GUIDE
8
Customer Service Tel. 763-502-0200 Customer Service Fax 763-502-0300
ENTEGRIS, INC.
ENTEGRIS, INC.
Customer Service Tel. 763-502-0200 Customer Service Fax 763-502-0300
9
NT® PRE SSU RE TRAN SDUCER USER GUIDE
Power Supply Requirements
Figure 1. Power Required for a 4-20 mA Loop
Load Resistance: Current Output
(4-20 mA Configuration)
If a load resistor, R
Load
, is used in
series with the current output, the
value of R
Load
is dependent on the
supply voltage and the meter resis -
tance and is calculated from the
following formula.
where:
R
Load
= maximum load
resistance (ohms)
V
PS
= power supply voltage (volts)
R
meter
= meter resistance (ohms)
(typically not used, therefore R
meter
= 0)
R
wire
= resistance of
interconnecting wire
R
Load
=
- (R
meter
+ R
wire
)
V
PS
- 12 V
0.020A
Operating
region
Power Supply Voltage
(V
PS
)
12
24
28
800
0
The pressure transducer requires a
12-28 volt DC power supply with less
than 2% ripple at 100 or 120 Hz. The
required power supply voltage varies
with the load resistance (R
Load
),
please refer to the diagrams below
and the formulas on page 9.
The power supply must provide
clean
power and must be used only
to power similar measurement-type
devices. The power supply must not
be used to power inductive loads,
such as motors, relays or solenoids.
These devices may produce tran-
sients that may affect the pressure
transducer measurements when the
inductive device is powered-up or
powered down.
NOTE:
Be sure to ground the
shield of the cable to local ground.
