PSM1700 PsimetriQ user manual
14-2
For “shunt” connection, shown above, the current is
measured directly across the shunt using CH2 while the
voltage across the Zx is measured by CH1. Notice that the
positive inputs to both CH1 and CH2 are connected to the
midpoint to minimise common mode loading effects.
Then : Zx = Zs x CH1 / CH2
Zs
+ +
GEN CH1
- -
+
CH2 Zx
-
For “divider Zx low” connection, shown above, the total
voltage is measured by CH1 and the voltage arising from
the potential divider effect of Zs and Zx is measured by
CH2. Notice that all the negative terminals are connected
together.
Then: Zx = Zs / ((CH1 / CH2) – 1)
The connections for “divider Zx high” are the same as
above but with Zx in the high arm of the potential divider
and the shunt in the low arm.
Then: Zx = Zs x ((CH1 / CH2) – 1)