Peekel Instruments PICAS - Full-Bridge

Peekel Instruments User manual PICAS V2.6.1
Page 9 of 59
2.1.4 Full-bridge
Figure 1 shows the connection of a full straingauge-bridge. This is the most reliable
configuration. The leadwire-resistances affect only the sensitivity of the bridge. For instance
6Ω resistances in both the + EX as well as the - EX wire, connected to a 120Ω bridge, give a
decrease in outputsignal of 9.1%. This can be compensated by using the internal sense
circuit. However, that does not compensate the temperature-influence on the leadwire-
resistance. A temperature-coefficient of 0.4%/°C on 12Ω of copperwire, connected to a
120Ω bridge, will still give 0.04%/°C change in sensitivity. Short, thick cabling is therefore
recommended.
-EX
+EX
9 polig
male Sub D
+SE
-SE
-
IN
+IN
-EX
+EX
-
IN
+IN
5
9
6
1
SIGNAL
Connect cable screen to
connector case.
Figure 1: Full-bridge, 4-wire, straingauge-connection
+SE
-EX
+EX
9 polig
male Sub D
+SE
-SE
-IN
+IN
-EX
+EX
-
IN
+
IN
-SE
5
9
6
1
SIGNAL
Connect cable screen to
connector case.
Figure 2: Full-bridge, 6-wire, straingauge-connection