Pulsar Measurement IMP Lite, Инструкция по эксплуатации

Страница: 15 / 38

PULSAR MEASUREMENT
15
Loop Resistance
The maximum cable resistance allowable can be calculated from the graph
below. For example, if an IMP Lite were supplied from a 24VDC, the
maximum total cable resistance is 590 ohms, for a typical 77 ohm /km cable
this would mean a maximum cable length of 590/77 = 7.6km, remember this
is the total cable resistance, so this figure must be divided by 2 to give 3.8km
max distance.
Maximum cable resistance vs supply voltage for 2 wire mode.
Preparation for Operation
Before switching on, check the following:
• The IMP Lite is mounted correctly.
•
The power supply is correctly installed.
Maintenance
There are no user serviceable parts inside your IMP Lite if you experience
any problems with the unit, then please contact Pulsar Process Measurement
for advice.
Allowable total cable resistance for Loop-
powered IMP
0
100
200
300
400
500
600
700
800
900
1000
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Supply Voltage
T
o
ta
l
C
a
b
le
r
e
s
is
ta
n
c
e
Important Notice
If the equipment is installed or used in a manner not specified in this
manual, then the protection provided by the equipment may be impaired.