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Calibration Weights:
Achieving Precision in Measurement

Ensuring the accuracy of a scale involves calibrating it against a known documented weight, verifying that it aligns with the manufacturer's specified standards. Some scales come with an internal calibration feature for added convenience, but for models without this feature, it is necessary to identify suitable external calibration weights.

The calibration weights chosen for this process must meet specific criteria in terms of accuracy and weight class. Generally, it is advisable to select calibration weights with an accuracy at least equal to 1/3 of the scale's readability. Having a variety of weight values available for testing is also ideal.

Determining the appropriate calibration weight class involves understanding the assigned class based on accuracy or tolerance. Various governing bodies, such as ASTM, NIST, and OIML, establish weight classes with distinct requirements. For a comprehensive guide on calibration weight classes, particularly focusing on ASTM and NIST systems, which are widely utilized in the United States, you can refer to our detailed calibration weight class guide. This guide explores the nuances of these systems to help you make an informed decision tailored to your specific application.

Test Weights

Types of Test Weights


Grip Handle Weights

Grip handle weights feature built-in handles or grips that make them easy to handle and transport. These weights are commonly used in industrial settings for calibrating scales and testing material handling equipment. Grip handle weights are available in various shapes and sizes, with the handles designed for ergonomic comfort and ease of use.


ASTM Class Weights

ASTM Class weights are precision weights that meet specific standards set by the American Society for Testing and Materials (ASTM). These weights undergo rigorous testing and certification processes to ensure accuracy and consistency. ASTM Class weights are available in various classes, ranging from Class 0 (the highest accuracy) to Class 7 (the lowest accuracy), depending on the intended application and calibration requirements.


Cast Iron Weights

Cast iron weights are commonly used for heavy-duty industrial applications due to their durability and resistance to wear and tear. These weights are often used for testing and calibrating industrial scales and heavy-duty weighing equipment. Cast iron weights are available in various shapes and sizes, including cylindrical, rectangular, and slotted designs.


Analytical Weights

Analytical weights are precision weights used for calibrating analytical balances and precision weighing instruments. These weights are manufactured with the highest level of precision and accuracy, often with tolerance levels down to micrograms or milligrams. Analytical weights are typically made from materials such as stainless steel or aluminum and are handled with extreme care to prevent contamination or damage.

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