HBM PX401, Operating Manual

Page: 182 / 552

Internal calculation channels
182
A4354-2.2 HBM: public
PMX
13.2.1.6 SG stress analysis
Function Biaxial stress analysis with strain gage rosette A, B, C
(0° / 45° / 90° or 0° / 60°/ 120°).
The temperature can be compensated by either of two
options:
Option A: By a separate strain from a gauge that shall have
the same temperature as A, B, C, but shall be free from strain.
Option B: By the apparent strain that comes from a
polynomial, provided that the temperature reading is available.
ε
actual
: strain used for stress calculation
ε
read
: strain read from gauges A, B, or C in μm/m
ε
T
: strain read from gauge T in μm/m
ε
p
: apparent strain from polynomial in μm/m
Do not use options A and B at a time. If the strains A, B, C
come already compensated, use neither of the options.
Unused inputs must be connected to constant 0.0.
Zero setting capability
The strains A, B, C don’t need to be set to zero. This function
block provide a set-to-zero trigger input, that clears all outputs.
Setting to zero may happen before each measurement or
once in a lifetime. The result is stored with the other settings
and will restore after starting up the device.
Inputs - Strain gauge A (0°, reference of angle) in μm/m
- Strain gauge B (45° / 60°) in μm/m
- Strain gauge C (90° / 120°) in μm/m
- Strain gauge T (optional ), temperature compensating strain
gauge in μm/m
- Apparent strain ε
p
from polynomial in μm/m
- Reset, a digital input that clears the outputs except the
angle phi