Hioki RM3542-50, Instruction Manual

Page: 223 / 234

Appendix 9 Zero Adjustment
A
17
Appendix
To perform zero adjustment appropriately
Table 1 shows the correct and incorrect connections. The resistances in the figure indicate
lead resistances; there will be no problem if they are less than a few
Ω
respectively.
As in (a), when H
POT
and L
POT
, and H
CUR
and L
CUR
are connected respectively, and if POT
and CUR are connected in a circuit, a potential difference will not be generated between H
POT
and L
POT
and 0 V is input. This enables zero adjustment to be carried out correctly.
On the other hand, as in (b), when H
POT
and H
CUR
, and L
POT
and L
CUR
are connected
respectively, and if Hi and Lo are connected in a circuit, the voltage of
I
×
R
Short
will be gen-
erated between H
POT
and L
POT
. For this reason, the pseudo 0
Ω
connection state cannot be
achieved and zero adjustment cannot be carried out correctly.
Table 1: Connection Methods
(a) Use one point each between POT-
CUR for connection
(b) Use one point each between Hi and
Lo for connection
Resistance between H
POT
and L
POT
R
SEH
+
R
SEL
R
SEH
+
R
Short
+
R
SEL
Flow path of
measurement current I
R
SOH
→
R
SOL
R
SOH
→
R
Short
→
R
SOL
Voltage generated
between H
POT
and L
POT
0
I
c
R
Short
As connection method for
zero adjustment
Correct Wrong
Connection
Methods