Measurement Computing WaveBook rev.3.0 - Manual (Page 61)

WaveBook User’s Manual, ch03B 6-23-99 WBK Expansion Options, WBK16 3-29
Half-Bridge Configurations
The half-bridge has two strain-variable elements and requires two internal bridge completion resistors
(BCRs). Any bridge resistance from 60 to 1000 ohms can be accommodated for either the internal or
external bridge.
Half-Bridge (+), Any Resistance from 60 to 1000 Ohms,
B,D, or F Shunt
IA
External
Bridge DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
1
8
9
7
5
4
3
6
2
In this connection, excitation voltage is
regulated at the connector. This
configuration should only be used for
short cable lengths. Output polarity can
be altered by selecting the software invert
function. The B, D, or F shunt resistor
may be software selected. Output polarity
during shunt calibration will be
automatically corrected by software.
IA
External
Bridge
DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
Half-Bridge (+), with Remote Sense
1
8
9
7
5
4
3
6
2
In this connection, excitation voltage is
regulated at the strain gage. This is the
preferred connection for longer cables.
3-Wire TC Half-Bridge, Software Invert & B, D, F Shunt Available
IA
External
Bridge DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
1
8
9
7
5
4
3
6
2
This occasionally utilized connection can
be made as shown. Two resistors
normally reserved for quarter-bridge
completion must be used. For
compatibility with other configurations,
the above two configurations are
preferred instead of this one.