The process of verifying an extensometer to ASTM E83 is a rigorous calibration procedure.
Step 1: Reference Standards The verification must be performed using a device capable of applying known displacements. Common devices include:
Step 2: Environmental Control The standard requires the test to be conducted within a specific temperature range (usually 20°C ± 2°C or similar) because thermal expansion can affect the calibration of both the extensometer and the reference standard.
Step 3: Mounting The extensometer is mounted onto the calibration rig in a manner identical to how it would be used on a specimen. Care must be taken to avoid applying torque or stress that could skew the reading. astm e83 pdf
Step 4: Data Collection The operator applies a series of displacements throughout the measuring range of the extensometer.
Step 5: Error Calculation For each calibration point, the error is calculated as: $$Error = \frac\textIndicated Strain - \textTrue Strain\textTrue Strain \times 100%$$
The absolute value of this error is compared against the table of allowable limits for the target Class. The process of verifying an extensometer to ASTM
To determine a class, three main parameters are evaluated:
When you buy a new extensometer, the manufacturer provides a certificate of conformance to ASTM E83. Using the astm e83 pdf, you can validate the certificate. Look for these three elements:
If the certificate claims "Class B-1" but does not specify the range, the certificate is non-compliant with the standard. Step 2: Environmental Control The standard requires the
Free PDFs are usually:
A: The PDF requires a minimum of 10 evenly spaced increments over the range of the extensometer.
ASTM standards are copyrighted material. Hosting or downloading a PDF from a third-party website (like Scribd, Academia.edu, or suspicious Russian file-hosts) is a violation of intellectual property law. ASTM is notoriously aggressive in protecting its standards.
The standard does not tell you how to build an extensometer; it tells you how to prove it works. It establishes a uniform method for classifying extensometers into specific accuracy classes (Class B-1, B-2, C, D, E, etc.) based on the relative error of the strain measurement.
If you are performing a tensile test according to ASTM E8 or ASTM A370, you cannot legally claim compliance unless your extensometer meets the requirements of ASTM E83.