Standard Practices for Verification of Speed for Material Testing Machines

Importancia y uso:

4.1 Material testing requires repeatable and predictable testing machine speed. The speed measuring devices integral to the testing machines may be used for measurement of crosshead speed over a defined range of operation. The accuracy of the speed value shall be traceable to a National or International Standards Laboratory. Practices E2658 provides procedures to verify testing machines, in order that the indicated speed values may be traceable. A key element to having traceability is that the devices used in the verification produce known speed characteristics, and have been calibrated in accordance with adequate calibration standards.

4.2 Verification of testing machine speed at a minimum consists of either or both of the following options:

4.2.1  Verifying the capability of the testing machine to move the crosshead at the speed selected.

4.2.2 Verifying the capability of the testing machine to adequately indicate the speed of the crosshead.

4.3 Where applicable, determine the testing machine's ramp-to-speed condition. This condition can be significant especially when verifying fast speeds or testing conditions with very short testing durations.

4.4 This procedure will establish the relationship between the actual crosshead speed and the testing machine indicated speed and or selected setting. It is this relationship that will allow confidence in the reported displacement over time data acquired by the testing machine during use.

Note 1: Many material tests never reach the desired test speed. Unless the actual data from the material test is examined, it is often impossible to know if the test speed has been reached or is repeatable from test to test.

Subcomité:

E28.01

Referida por:

E0008_E0008M-24, D8444_D8444M-24, E0009-19, E0008_E0008M-24, E0009-19, E0008_E0008M-24

Volúmen:

03.01

Número ICS:

19.060 (Mechanical testing)

Palabras clave:

accuracy; classification; crosshead speed; ramp-to-speed condition; speed measuring system;