4
LOOP RESISTANCE
Maximum loop resistance can be calculated by:
V power – 12 V
R
L
(max) =
20 mA
Loop resistance is the sum of the wiring resistance and
the load resistance.
Typical
POWER SOURCE
VOLTAGE
R
L
(max)
20
400
Ω
24
600
Ω
26
700
Ω
Reference: Robertshaw cable resistance is 40
Ω
per thousand feet.
Typical Circuit
White
Pin A
DC Power
Pin B Black Supply
RLoad
Model 570B
Signal Measuring Circuit
Due to continued research and development, the manufacturer
reserves the right to amend these specifications without notice.
Q-4166 (8/01) Printed in U.S.A.
