This model measures axial strain on opposite sides of the test specimen with independent outputs making the BD 25/50 suitable for the determination of the Young's modulus on concrete in accordance with EN 12390-13, ASTM C469, ISO 6784 and DIN 1048-5.
The test procedure according to EN 12390-13 assess that the specimen centring should be controlled twice. The first time after the second loading and unloading cycle, and the second time after the third loading. After the second cycle of lading and unloading the deviation of the strain values of the two sides cannot excel +/-20% of the mean strain values. When the difference is greater, the specimen should be centred again. In the case of a second control, the difference may not exceed 10% of the strain average value.
When this extensometer is used with our Proteus application software, beside of the average value also both single values are displayed with automatic observation of the deviation in accordance with EN 12390-13.

Features

• Full bridge 350 ohm strain gaged design for compatibility with nearly any test system

• High accuracy unit

• Dual independent output (averaging box optional available)

• Suitable for large range of specimen sizes and shapes

• Easy mounting

• Self-supporting on the specimen

• Adjustable clamping force

• Supplied in high quality wood lined case