Measurement and Control Module Operators Manual

SECTION 13. CR10 MEASUREMENTS
13-19
FIGURE 13.5-2. Excitation and Measurement Sequence for 4 Wire Full Bridge
TABLE 13.5-1. Comparison of Bridge Measurement Instructions
Instr. # Circuit Description
4 DC Half Bridge The delay parameter
allows the user entered
settling time com-
pensate for capacitance
in long lead lengths. No
polarity reversal. One
single-ended measure-
ment. Measured
voltage output.
5 AC Half Bridge Rapid reversal of
excitation polarity for
ion depolarization.
One single-ended
measurement at each
excitation polarity.
Ratiometric output.
6 4 Wire One differential
Full Bridge measurement at each
excitation polarity.
Ratiometric output.
Instr. # Circuit Description
7 3 Wire Compensates for lead
Half Bridge wire resistance,
assuming resistance is
same in both wires.
Two single-ended
measurements at each
excitation polarity.
Ratiometric output.
8 Differential Makes a differential
Measurement measurement without
with Excitation reversing excitation
polarity. Used for fast
measurements on load
cells,
PRTs etc.
Resolution and
common mode rejection
worse than 6 if used
with delay = 0.
Measured voltage
output.
9 6 Wire Compensates for lead
Full Bridge wire resistance. Two
or 4 Wire differential measure-
Half Bridge ments at each
excitation polarity.
Ratiometric output.