YOKOGAWA 701957 User manual

User’s
Manual Model 701957 Bridge Head
(DSUB-120 Ω, Shunt CAL,
Enhanced Shield)
Model 701958 Bridge Head
(DSUB-350 Ω, Shunt CAL,
Enhanced Shield)
IM 701957-01E
2nd Edition

1
IM 701957-01E
Foreword
Thank you for purchasing the bridge head (701957/701958).
This User’s Manual contains useful information about the function, procedures in
connecting the gauge, and handling precautions of the bridge head. To ensure correct
use, please read this manual thoroughly before operation.
Keep the manual in a safe place for quick reference in the event a question arises.
Notes
•The contents of this manual are subject to change without prior notice as a result of
continuing improvements to the device’s performance and functions.
•Every effort has been made in the preparation of this manual to ensure the accuracy
of its contents. However, should you have any questions or find any errors, please
contact your nearest YOKOGAWA dealer as listed on the back cover of this manual.
•Copying or reproducing all or any part of the contents of this manual without
YOKOGAWA’s permission is strictly prohibited.
Revisions
•1st Edition: February, 2003
•2nd Edition: October, 2017
Disk No. DL40
2nd Edition: October 2017 (YMI)
All Rights Reserved, Copyright © 2003 Yokogawa Electric Corporation
All Rights Reserved, Copyright © 2017 Yokogawa Test & Measurement Corporation

2IM 701957-01E
Checking the Contents of the Package
Unpack the box and check the contents before using the device. If the contents are not
correct or missing or if there is physical damage, contact the dealer from which you
purchased them.
Bridge Head
Check that the model name given on the name plate match that on the order. When
contacting the dealer from which you purchased the device , please quote the device
No.
Made in Japan
Model
Model Specifications Description
701957 Bridge resistance 120 ΩShunt CAL, enchanced shield
701958 Bridge resistance 350 ΩShunt CAL, enchanced shield
No. (Device number)
When contacting the dealer from which you purchased the device, please quote this
number.
Standard Accessories
D-Sub cable
(for 701957, 701958)
B8023WP
Length: 5 m
Attaching Plate
B9947KR
2 Binding screws
(M4 × 5 mm)
This User’ Manual

3
IM 701957-01E
Conventions Used in this Manual and on the Device
Symbols Used on the Device
GND terminal
The operator must refer to an explanation in the User’s Manual.
Symbols Used in this Manual
Note
Provides important information for the proper operation of the device.

4IM 701957-01E
Contents
Foreword ........................................................................................................................................ 1
Checking the Contents of the Package .......................................................................................... 2
Conventions Used in this Manual and on the Device ..................................................................... 3
1Construction of the Device .................................................................................................. 5
2Shunt Calibration ................................................................................................................ 7
3Connecting the Strain Gauge .............................................................................................. 8
4Fixing the Device in Place ................................................................................................. 10
5Connecting to the Strain Instrument ................................................................................. 11
6Calibrating Using a Shunt Resistor ................................................................................... 12
7 Specifications .................................................................................................................... 16

5
IM 701957-01E
1Construction of the Device
The bridge head is a converter for inputting the amount of change of the resistance of
the strain gauge to the amplifier. Six types of connection methods (single-gauge, single-
gauge three-wire, adjacent-side two-gauge, opposed-side two-gauge, opposed-side two-
gauge three-wire, and four-gauge) are supported by setting the switch.
Names of the Parts
Cable
B8023WP
Connector
Switch
Strain gauge
connection terminal
GND terminal
Connect to a measuring instrument.
Shunt resistant
connection terminal
Terminals and Circuit Diagram
1
2
3
4
5
6
7
8
9
1
2
345
76
8
9
1
2
3
4
5
7
6
8
9
7
9
8 3 2 5 6
4
1
1
Bridge+
Bridge+
Bridge-
Bridge-
Input+
Input+
Input-
Input- Sense+
Sense+
Sense-
Sense- Suntcal+
Suntcal+
Suntcal-
Floating Common
Suntcal-
Shell
R
R
R
2
3
BRIDGE HEAD(120 )
GAUGE SELECT
SHUNT RESISTANCE
SW
ON
OFF
12345
123456
789 78978 9
STRAIN GAUGE
SHUNT CALSHUNT CAL
4GAUGE2GAUGE
1GAUGE
1GAUGE 2GAUGE 4GAUGE
(SHUNT CAL, ENHANCED SHIELD)
Strain gauge
connection
terminal
Switch
D-Sub connector
GND terminal
GND terminal
(Terminal
number)
(Switch number)
Pin Signal name
symbol Floating common
Sense– (Sensing of the bridge voltage-)
Shuntcal–(Shunt signal–)
Shuntcal+(Shunt signal +)
Sense+ (Sensing of the bridge voltage+)
Bridge– (Bridge voltage –)
Input– (Measurement signal –)
Input+ (Measurement signal +)
Bridge+ (Bridge voltage +)
Pin assignments of the connector (Bridge head side)
Shunt resistant
connection
terminal
The numbers inside are the terminal
numbers.
The numbers inside are the switch
numbers.
The numbers inside are the pin
numbers of the connector.

6IM 701957-01E
Wiring for Accessory Cable B8023WP
A wiring diagram for the accessory cable is given below. The connector shell connects
to the shielding.
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+
Bridge-
Input+
Input-
Sense+
Sense-
Shuntcal+
Shuntcal-
Floating Common
1
5
6
9
1
5
6
9
Bridge+
B8023WP
Bridge-
Input+
Input-
Sense+
Sense-
Shuntcal+
Shuntcal-
Floating Common
Note
Check the shape and pin assignment of the connector before connecting it to the accessory
cable.
Circuit Diagram for Bridge Head and Measuring Instrument
The circuit diagram below shows the bridge head connected to a measuring instrument
(the DL750). Isolate the strain gauge before use.
CAUTION
Do not connect the strain gauge terminal to any items with electric potential.
B8023WP
Bridge+
Bridge+
Bridge-
Bridge-
Input+
Input+
Input-
Input-
Sense+
Sense+
Sense-
Sense-
Shuntcal+
Shunt resistor
Shuntcal-
Shuntcal+
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+
Bridge-
Input+
Input-
Sense+
Sense-
Suntcal+
Suntcal-
Floating Common
Floating
Common
Floating
Common
ON/OFF
Shuntcal-
Sense+
+
-
Sense-
Sense+
Sense-
701271
STRAIN_DSUB
AD
Bridge
Power
+
-
Shuntcal
Shuntcal+
*2
The connector shell
is connected to the
case potential of the
bridge head.
Bridge Head 701957/701958
(with shunt calibration support)
GND
terminal
Measurement instrument
(example: DL750)
All module
signals are
isolated.
Module
Case
Case
The connector shell is connected
to the case potential of the
measurement instrument.
*2
*1 The GND (floating common) of the module is connected to the case potential inside the bridge head.
*2 The bridge head case, the cable shield, and the measurement instrument case are connected as measures against noise.
*2
The shield is connected
to the bridge head case
and the measurement
instrument case.
*1
The floating common of the
module is grounded within
the bridge head.
1 Construction of the Device

7
IM 701957-01E
2Shunt Calibration
This instrument supports shunt calibration. When executing shunt calibration, perform
balancing without applying a load to the strain gauge, then turn on shunt resistance. The
values from the shunt resistance are stored on the measuring instrument.
P2:X
P2:Y
Balance Shunt calibration
Strain Strain
Before execution
Before execution
After execution
After execution
Strain input Strain input
The zero point is corrected
when balancing is executed.
Current measured
value*
Gain is corrected.
The strain value corresponding to
the shunt resistor is set to P2:Y of
the setup menu.
* Automatically obtained when shunt calibration is executed.
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. With this instrument, the gain can be corrected on both the positive and negative
sides. Make sure to notice whether the corresponding strain values are positive or
negative.
When correcting the gain on the negative side (normal)
Shunt resistor insertion terminal: between 8 to 9
Set negative to the corresponding strain value.
789Bridge+
Bridge-
In+
120 Ω
120 Ω
120 Ω
In-
Shunt calibration relay
circuit (Built into the
strain module. Turns
ON/OFF automatically
when shunt calibration
is executed.)
Shunt resistor
(Applied to the bridge head)
Bridge
voltage
Shunt resistor
Strain
gauge
Shunt resistant
connection terminal
When correcting the gain on the positive side
Shunt resistor insertion terminal: between 7 to 8
Set positive to the corresponding strain value.
Bridge+
Bridge-
In+
In-
789
120 Ω
120 Ω
120 Ω
Shunt calibration relay
circuit (Built into the
strain module. Turns
ON/OFF automatically
when shunt calibration
is executed.)
Shunt resistor
(Applied to the bridge head)
Bridge
voltage
Shunt resistor
Strain
gauge
Shunt resistant
connection terminal
For specific instructions on performing shunt calibration, refer to your measuring
instrument’s user’s manual. For information on shunt resistance and the corresponding
strain values, see page 13 in “Calculation of the Shunt Resistance.”

8IM 701957-01E
3Connecting the Strain Gauge
The bridge head can support six types of connection methods: single-gauge, single-
gauge three-wire, adjacent-side two-gauge, opposed-side two-gauge, opposed-side two-
gauge three-wire, and four-gauge.
Do not connect the strain gauge terminal to any items with electric potential.
CAUTION
Do not connect the strain gauge terminal to any items with electric potential.
Use the lead wires included with the strain gauge or wires meeting the following
specifications to connect the strain gauge and the bridge head.
•Usable wire: single wire φ 0.14 to 1.5 mm2, or stranded wire 0.14 to 1.5 mm2 (AWG26
to 16)
• Normal length of bare wire : 6 mm
Note
•Isolate the strain gauge before use.
•Make the wires between the strain gauge and bridge head as short as possible.
•Proper measurements may not be possible in an environment where electromagnetic
interference exists.
•If you are shielding the strain gauge, connect the shield wire to the floating common
terminal of the bridge head.
• For the handling of the strain gauge, see the instruction manual that came with the shield
gauge.
Single-gauge Method
ON
OFF
1
2
3
4
5
6
12345
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
1
23
4
56
9
8
7
Bridge+
Sense+
Bridge-
Sense-
Input+
Input-
Shuntcal-
Shuntcal
ON/OFF
Shuntcal+
Bridge head terminal
Strain gauge
Strain gauge
Shunt
resistor
Switch setting of
the bridge head
Single-gauge Three-wire Method
ON
OFF
1
2
3
4
5
6
12345
1
23
4
56
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
9
8
7
Bridge+
Sense+
Bridge-
Sense-
Input+
Input-
Shuntcal-
Shuntcal+
Shuntcal
ON/OFF
Bridge head terminal
Strain gauge
Strain gauge
Shunt
resistor
Switch setting of
the bridge head

9
IM 701957-01E
Adjacent-Side Two-gauge Method
ON
OFF
1
2
3
4
5
6
12345
1
3
4
56
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
Bridge+
Sense+
Bridge-
Sense-
Input-
Input+
Bridge head terminal
Strain gauge
Strain gauge
Strain gauge
Switch setting of
the bridge head
Opposed-Side Two-gauge Method
ON
OFF
1
2
3
4
5
6
12345
1
23
4
56
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
Bridge+
Sense+
Bridge-
Sense-
Input-
Input+
Bridge head terminal
Strain gauge
Strain gauge
Strain gauge
Switch setting of
the bridge head
Opposed-Side Two-gauge Three-wire Method
ON
OFF
1
2
3
4
5
6
12345
1
23
4
56
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
Bridge+
Sense+
Bridge-
Sense-
Input-
Input+
Bridge head terminal
Strain gauge
Strain gauge
Strain gauge
Switch setting of
the bridge head
Four-gauge Method
ON
OFF
1
2
3
4
5
6
12345
1
3
4
6
Bridge+ (Sense+)
Input- (Shuntcal-)
Bridge- (Sense-)
Input+
Bridge+
Sense+
Bridge-
Sense-
Input-
Input+
Bridge head terminal
Strain gauge Strain gauge
Strain gauge
Strain gauge
Strain gauge
Switch setting of
the bridge head
3 Connecting the Strain Gauge

10 IM 701957-01E
4Fixing the Device in Place
If necessary, you can use the accessory attaching plate, B9947KR, to fix the bridge head
to the panel.
1. Align the small holes on the bottom side of the bridge head to the small projections
of the attaching plate.
2. Screw the bridge head and the attaching plate together using the accessory
binding screws (M4 × 5 mm).
Bridge head
Attaching
plate
B9947KR
Binding screws (M4 x 5mm)
Projections

11
IM 701957-01E
5Connecting to the Strain Instrument
The bridge head uses a D-Sub 9-pin connector. The accessory cable, B8023WP, is used
to connect to the strain instrument.
Strain instrument
Accessory cable
B8023WP
Bridge head

12 IM 701957-01E
6Calibrating Using a Shunt Resistor
Shunt calibration can be performed by combining with the YOKOGAWA's strain module
(Model 701271 (STRAIN_DSUB) that supports shunt calibration.
Connection procedures for the shunt resistor
The following two connection methods are available. In normal cases, connect the
resistor in correcting the gain on the negative side.
7
9
8 3 2 5 6
4
1
Bridge+
Bridge-
Input+
Input-
Sense+
Shuntcal
ON/OFF
Sense-
Shuntcal+
Shuntcal-
Shuntcal+
Shuntcal-
R
R
R
789789
Bridge
voltage
Strain
gauge
Example for single-gauge method
Shunt resistor
(negative side)
Shunt resistor
(positive side)
Shunt resistant
connection terminal
Shunt resistant
connection terminal
Shunt resistor Shunt resistor
When correcting the gain on
the negative side (normal)
When correcting the gain on
the positive side

13
IM 701957-01E
Calculation of the Shunt Resistance
Shunt calibration and shunt resistance
To execute shunt calibration, the shunt resistance (Rs) and the expected strain (ε) need
to be calculated in advance. Use ε as given in the equation below (normally a negative
value). With the DL750 (model 7071271), enter the value into “P2-Y” under the shunt
calibration execution menu. However, when using the general method given for shunt
calibration (the easy method), an error of 1 to 2% can be introduced as the strain value
(ε) increases. Therefore, calculate using the detailed method whenever possible. Also,
you must select a setting range value that will not result in an overrange.
Equation for Rs and e When Executing Shunt Calibration
•General Equation
∆R/R = K×ε(1): Basic Equation of Strain
∆R = R–R//Rs (2): Equation of the change in resistance when the shunt
resistance is ON
Note:In this manual, the parallel equation of resistors are expressed as follows:
R//Rs= =
1
R
R×Rs
R+Rs
1
1
Rs
+
ε: Strain (strain you wish to generate when the shunt resistance is turned ON)
K: Gauge factor
R: Bridge resistance
∆R: Resistance change
Rs: Shunt resistance (shunt resistance you wish to derive)
If ∆R is cancelled out from (1) and (2),
Rs=R×(1-K×ε)/(K×ε)(Equation A): General equation used to calculate the
shunt resistance (includes error)
6 Calibrating Using a Shunt Resistor

14 IM 701957-01E
•Detailed Equation
(1): Basic Equation of Wheatstone Bridge
(2): Equation when turned ON
(3): Equation of combined resistance R'
(4): Since R1 to R4 are equal, we represent
them as R
(5): Basic equation of strain
E: Bridge voltage
V0: Bridge output voltage
R1 to R4: Bridge resistance (except, R1=R2=R3=R4)
Rs: Shunt resistance (shunt resistance you wish to derive)
R': Combined resistance when the relay is turned ON (R'=R//Rs)
V0=E×(R1×R3–R2×R4)/{(R1+R2)×(R3+R4)}
When shunt calibration is ON,
V0=E×(R1×R3–R'×R4)/{(R1+R')×(R3+R4)}
R'=R2//Rs
R1=R2=R3=R4=R
Also, from the basic equation of strain,
V0/E=K×ε/4
If V0/E and R1 to R4 are cancelled out from (2), (3), (4), and (5),
Rs=R×(1–K×ε/2)/(K×ε)(Equation B): Detailed equation used to calculate
the shunt resistance (no error)
E (Bridge power supply)
R4 R1
V0
R2R3
Rs
6 Calibrating Using a Shunt Resistor

15
IM 701957-01E
6 Calibrating Using a Shunt Resistor
Calculation Example
•When Determining the Corresponding Shunt Resistance (Rs) from the Strain (ε)
Given a gauge factor (K) of 2,
Detailed equation Rs = R×(1–ε)/(2×ε)(6)
(equation B)
General equation Rs = R×(1–2×ε)/(2×ε)(7): Error of 1 to 2% present
(equation A)
Desired Strain Derived by the Detailed Equation (6) Rs value (Ω) Derived by the
ε (µSTR) Rs Value (Ω)General Equation (7)
R=120 ΩR=350 ΩR=120 ΩR=350 Ω
1,000 59,940 174,825 59,880 174,650
2,000 29,940 87,325 29,880 87,150
5,000 11,940 34,825 11,880 34,650
10,000 5,940 17,325 5,880 17,150
• When Determining the Corresponding Strain (e) from the Shunt Resistance (Rs)
If we derive e from equation (6) and (7),
Detailed equation ε = 1/(1+2×Rs/R) (8)
(equation B)
General equation ε = 1/{2×(1+Rs/R)} (9): Error of 1 to 2% present
(equation A)
When the Bridge Resistance R is 120 W
RS Value (Ω) Strain ε (µSTR) Derived by Strain ε (µSTR) Derived by
the Detailed Equation (8) the General Equation (9)
60,000 999 998
30,000 1,996 1,992
12,000 4,975 4,950
6,000 9,901 9,804
When the Bridge Resistance R is 350 W
RS Value (W) Strain ε (µSTR) Derived by Strain ε (µSTR) Derived by
the Detailed Equation (8) the General Equation (9)
180,000 971 970
90,000 1,941 1,937
36,000 4,838 4,814
18,000 9,629 9,537
For the procedures related to performing the shunt CAL, see the manual that came with
the strain module that you are using.
Shunt CAL may not operate correctly on some strain measurement instruments. Check
this with the manual that came with the strain measurement instrument.

16 IM 701957-01E
7Specifications
Bridge resistance
Model 701957: 120 Ω
Model 701958: 350 Ω
Applicable gauge methods
Single-gauge
Single-gauge three-wire
Adjacent-side two-gauge
Opposed-side two-gauge
Opposed-side two-gauge three-wire
Four-gauge
Operating conditions
Temperature: 5 to 40°C
Humidity: 20 to 85% RH
External dimensions
Approx. 50(W) × 101(H) × 29(D) mm
Weight
Approx. 100 g (Bridge head only)
Standard accessories
Cable (part no.: B8023WP): 1 piece, with D-Sub connector, 5 m in length
Attaching plate (part no.: B9947KR): 1 piece, with two M4 binding screws
User’s manual: 1 piece, this manual

17
IM 701957-01E
External drawings
Bridge head
101
96
50
18
29
BRIDGE HEAD(120 )
GAUGE SELECT
SHUNT RESISTANCE
SW
ON
OFF
12345
123456
789 78978 9
STRAIN GAUGE
SHUNT CALSHUNT CAL
4GAUGE2GAUGE
1GAUGE
1GAUGE 2GAUGE 4GAUGE
(SHUNT CAL, ENHANCED SHIELD)
Attaching plate
119
5108
3.5
46
7 Specifications