App-19
IM 701240-01E
3
2
1
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
App
App
Index
Appendix
Appendix 10 Shunt Calibration of the Strain Module
Shunt calibration is used to correct the gain of strain measurements by inserting a known
resistance (shunt calibration resistance (shunt resistance)) in parallel with the strain
gauge. The Strain Module (701271(STRAIN_DSUB) supports shunt calibration and
contains a built-in relay circuit for shunt calibration.
To execute shunt calibration, a bridge head that supports shunt calibration (701957/
701958) is needed.
The floating common of the module is
grounded within the bridge head.
1
The shield is connected to
the bridge head case and
the measurement instrument
case.
The connector shell is
connected to the case
potential of the bridge
head.
2
1. The GND (floating common) of the module is connected to the case potential inside the bridge box.
2. The bridge head case, the cable shield, and the measurement instrument case are connected as measures against noise.
B8023WP
Bridge Head 701957/701958
(with shunt cal support)
Bridge-
Bridge-
Input+
Input+
Input-
Input-
Sense+
Sense+
Sense-
Sense-
S
Shunt resistor
Shuntcal-
S
Shuntcal-
R
R
R
9
6
8
7
5
2
4
3
1
Shell
Twist
Twist
Twist
Shield
Twist
9
6
8
7
5
2
4
3
1
Shell
Bridge-
Input+
Input-
Sense+
Sense-
S
Shuntcal-
Floating Common
Floating
Common
Floating
Common
ON/OFF
Shuntcal-
Sense+
+
-
Sense-
Sense+
Sense-
701271
STRAIN_DSUB
AD
Module
All module
signals are
isolated.
Bridge
Power
+
-
Measurement instrument
Shuntcal
S
Case
The connector shell is connected to the case
potential of the measurement instrument. 2
GND
terminal
Case
2
Bridge
voltage
Bridge-
In+
In-
Shunt resistor (Applied to the bridge head)
Shunt calibration relay circuit (Built into the strain
module. Turns ON/OFF automatically when shunt
calibration is executed.)
Bridge-
In+
In-
Shunt resistor, when correcting the positive side
120
Ω
120
Ω
120
Ω
• When correcting the gain on the negative side (normal)
Shunt calibration relay circuit (Built into the strain
module. Turns ON/OFF automatically when shunt
calibration is executed.)
Bridge
voltage
120
Ω
120
Ω
120
Ω
• When correcting the gain on the positive side