In a practical test, four HBM strain gauges of the LG11-6/350 type, adapted to steel (α=10.8 10-6/K), were installed on an aluminum workpiece. A four-wire circuit was used to eliminate cable influences. According to the data supplied by the manufacturer for the material, α=23.00 *10-6/K for T= 0 … 100°C.
ϑ (°C) | εa(*10-6) | εs(*10-6) | εa-εs(*10-6) | αb(*10-6)/K |
-10 | -396.9 | -38.0 | -358.9 | |
0 | -254.4 | -16.9 | -237.5 | 22.9 |
10 | -122.5 | -5.0 | -117.5 | 22.8 |
20 | 0 | -1.1 | 1.1 | 22.7 |
30 | 118.8 | -3.9 | 122.7 | 23.0 |
40 | 232.4 | -12.2 | 244.6 | 23.0 |
50 | 344.3 | -24.8 | 369.1 | 23.2 |
60 | 453.3 | -40.3 | 493.6 | 23.3 |
70 | 562.1 | -57.7 | 619.8 | 23.4 |
80 | 671.6 | -75.6 | 747.2 | 23.5 |
90 | 781.8 | -92.7 | 874.5 | 23.5 |
100 | 894.1 | -107.9 | 1002.0 | 23.5 |
110 | 1010.5 | -119.9 | 1130.3 | 23.6 |
120 | 1132.3 | -127.4 | 1259.8 | 23.7 |
Tab. 1 Measurement results for a strain gauge adapted for ferrit. steel, installed on aluminum