Calibration and Weights

Calibration weights are specially designed cast iron or stainless steel weights used to calibrate weighing equipment. Test weights are manufactured and laboratory compared to a certain degree of accuracy against a known standard.

Using a reliable and certified test weight to calibrate a scale is an important part of maintaining your scale’s accuracy, and a necessity if using the scale in Legal for Trade applications. Our dealership offers a wide selection of quality test weights for various applications.

Use the resources below to help select the right test weights for your application.

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ASTM Mass Reference Standards

Applications:

  • Calibrating Class I and II balances
  • Calibrating ASTM Class 4, 5 and 6 weights
  • Student laboratory use
  • Rough weighing operations
  • Force measuring operations
  • Tolerance testing
  • Verification checks 

OIML Mass Reference Standards

Applications:

  • Density measurement
  • Tolerance checking
  • Mass standards
  • OIML guidelines for balance and scale verification

ASTM Balance Calibration Weights

Applications:

  • Calibrating Class I and II balances
  • ASTM Class 4, 5 and 6 weights
  • Tolerance checking or verification of balances

ASTM Stainless Steel Field Weights

Applications:

  • Field standards for Class III scales or balances
  • Testing non-classified scale equipment
  • Tolerance checking

Cast Iron Field Weights

Applications:

  • Field standards for testing industrial devices Class III, Class IIIL or Class IIII
  • Testing for non-marked scales without class designation
  • Verifying scales are within specified accuracy and tolerances

Purchasing Calibration Weights

Before ordering test weights and weight sets, it is important to consider your application, the environment the test weights will be housed in, what tolerance and type of test weights you need as well as if you need any official documentation. Please use the following questions below to prepare your order. If there is missing information or if you have any questions regarding what you need, please call 800-451-0187.

Application or Environment

  1. Please describe your application and tell us what you need to accomplish with the weight(s) or weight set.
  2. What is the maximum amount of weight you will need at any one time?
  3. What is the minimum amount of weight you will need at any one time?
  4. Do you need something that is custom manufactured?
  5. What is your budget for this project?
  6. Tell us about your environment. Is it:
    1. Indoor/outdoor?
    2. Wet/dry?
    3. Windy/still?
    4. Corrosive, hazardous or explosive?
    5. A clean room?
    6. An environment with biohazard, electrostatic or magnetic conditions to consider?
    7. An environment with other noteworthy conditions? If so, what are they?
  7. Are you replacing an existing weight or weight set?
  8. If the answer to question number 7 is yes:
    1. What do you like/dislike about the existing weights?
    2. What configuration is the existing set?
    3. What style is the existing set?
    4. What laboratory documentation is needed for the existing set?
  9. Does this weight set need to be Legal for Trade?
  10. What other precision services/equipment (recalibration, balances, accessories, static electricity) do you use?

Tolerance or Type of Weights

  1. What tolerance are you looking for?
  2. Is your tolerance driven by the equipment under test, the application, an internal specification, a document or another source?
  3. What "style" (ASTM, OIML, NIST) is required or preferred?
  4. What configuration do you need (5-2-2-1, 5-3-2-1)?

 

Documentation 

  1. Do you need ISO/IEC 17025 and ISO 9000 laboratory documentation?
  2. If you do not need ISO/IEC 17025 and ISO 9000 laboratory documentation, do you need traceability to NIST?
  3. Do you need a true mass value?
  4. Do you need a book version of the Calibration Report?
  5. If you do not need any documentation, you still have the option of an RLWS Statement of Accuracy.
  6. If you are getting any of the laboratory documentation above, do you need a recall date?

 

Cases & Serial Numbers

  • OIML and ASTM test weight sets larger than 500 grams, or one pound, include a hardwood case with velvet-lined pockets. Test weight sets with the largest weight of 500 grams include a precision-machined polyvinyl, crush-resistant case.
  • Serial numbers are not stamped on polished or milligram weights. A test weight should be more accurate than the precision of the weighing device, and it is recommended that a test weight has an accuracy of one-third of the weighing device's readability. 

Request Information about Custom Calibration Weights

Submit the following information to request a custom or unique calibration weight and one of our customer service representatives will contact you shortly.

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