What are the different accuracy classes meant for weights?

Calibration weights are one of the most common tools that are utilized in labs. Almost every laboratory has them to verify whether the weighing balances are giving accurate readings or not. These calibration weights are made available by the respective manufacturers according to distinct accuracy classes.

If you are curious about the definition and standards defined for weights according to those classes, then we as the specialist manufacturer of calibration weights for laboratories in India find us capable of answering such queries. Let us elaborate some vital pieces of information to you regarding accuracy classes for weight.

Basic Introduction to Accuracy Classes for Weights

All calibration weights are made and assigned a class based on the accuracy or tolerance of the weight. There are several sets of accuracy classes defined for such weights, such as ASTM, OIML and NIST. Also, there are certain certifications granted to the respective types of weights. 

Here in this blog, being the expert manufacturer of calibration weights for laboratories in India we are going to explain different classes made according to the accuracy of the calibration weights and the certificates that can be obtained along with them. 

What are the Different Classes of Weights

There are three major sets of classes defined for the calibration weights. Most likely you will come across them while buying calibration weights for your laboratory-based purposes. 

• ASTM Classes: ASTM is an acronym of American Society for Testing and Materials. It is a non-profit non-governmental organization that has developed and defined consensus standards for the weights. According to ASTM, there are 10 calibration weight classes. These classes have been elaborated in the document ASTM E 617: ASTM Class 000 thru ASTM Class 7. In simple terms, the higher class number signifies a higher level of tolerance and hence, less accuracy for the corresponding weight. Laboratories usually prefer ASTM weights of Class 4 or below for attaining better efficiency in their applications. ASTM class weights are one of the most popular types of calibration weights used worldwide.

• OIML Classes: The term OIML stands for ‘Organisation Internationale de Métrologie Légale or International Organization of Legal Metrology’. OIML is an intergovernmental organization that has defined and provided the weight standards for harmonizing legal metrology processes. If we put in simpler words, the sequence of lowest tolerance (most accurate) to highest tolerance OIML classes is E1, E2, F1, F2, M1, M2, and M3. Most laboratories prefer to use OIML weights of Class F2 and below. OIML class weights are more commonly used globally, especially outside the US.

• NIST Standards: The term NIST stands for National Institute of Standards and Technology. NIST Class F is not usually preferred to be used in the laboratory settings as they are not accurate enough as required for the laboratories but fine to be used in general applications. The NIST Class F weights are the most popular class of weights that are used for verifying the setting of Class III, Class IV and other non-designated scales in industrial applications. These set of classes are also applicable in warehouses and manufacturing facilities for calibrating the weighing scales that are used during shipping or production of bulk products. 

If you are also dealing with laboratory work and looking for top-grade and accurate calibration weights, then get your needs accomplished with Swastik System and Services. We are one of the leading manufacturers and suppliers of calibration weights for laboratories in India and we offer an extensive range of such weights of distinct accuracy classes. Explore our range of calibration weights and we are confident enough that you will certainly find the suitable class of calibration weights as per your requirements.