COMPOUND MAGNIFICATION SYSTEM- Berry Strain Gauge

COMPOUND MAGNIFICATION SYSTEM Berry Strain gauge

It has Greater sensitivity The point b is rigidly fixed to the frame . The point c is pivoted from the frame and is integral with a lever arm d, which alone magnifies the strain about 5:1 The dial indicator permitting measurements of strain to the nearest 0.005 mm with a 0.025mm micrometer. The variations of micrometer contact pressure and seating of the conical points in holes, making the gauge length, probably reduce the accuracy to about 0.015mm

Tinius Olsen Extensometer

Tinius olsen strain gauge is a very compact and convenient instrument. This combines lever and an indicator in which the strain in the 5cm gauge length may be read to the nearest 0.0025mm micrometer. The knife contacts acting on opposite side of the specimen, gives an average of the strain values on the two sides with only one gauge reading. A cantilever spring acting on the specimen opposite each knife edge provides the necessary mounting force and contact pressure.

COMPOUND LEVER MAGNIFICATION- Porter- Lipp strain gauge

COMPOUND LEVER MAGNIFICATION These type of gauges are very sensitive to any vibration that may occur in the structure under test. The natural frequency of these gauge is rather low The gauge length of this gauge is 25mm and magnification 300 Advantages: Compactness Extreme light weight

HUGGENBERGER EXTENSOMETER

The magnification may vary from 300 to 2000 depending upon the model. The gauge length varies from 12.5 to 25 mm Advantages: Small size High magnification factor

MAGNIFICATION BY RACK AND PINION

COMBINED LEVER, RACK AND PINION MAGNIFICATION