These Sartorius calibration weights are sold individually with a choice of No Certificate, Traceabililty Certificate, or with a Certificate of Calibration. Your choice of certificates determine the price of your calibration weight.

ASTM: ASTM stands for American Society of Testing and Materials. The ASTM is an international organization that establishes and develops methods for testing materials. ASTM weights and weight sets are made to the tolerance, construction, finish, and magnetism set by them. ASTM requires that weights be made of one piece (no fillers or air to compensate for small adjustments). ASTM weights are recommended for calibrating other weights or high resolution balances.

Traceable Certificate: Many weights and weight sets are available with traceable certificates as an additional option. These certificates are issued by laboratories and manufacturers that are accredited by NIST/NVLAP, ASTM, and/or OIML depending on the type of weight, manufacturer, and class. These certificates are traceable to NIST and contain information such as type of weight, weight class, density, uncertainty, and environmental conditions at the time of calibration.

NVLAP: The National Voluntary Laboratory Accreditation Program (NVLAP). This program evaluates and accredits laboratories in their respective fields and ensures they meet ISO standards.