Scale.co.za / Technical guide

Test Weights and Calibration Weights

Test weights provide a known mass for checking whether a scale is responding correctly. The right choice depends on the scale division, capacity, required uncertainty, environment and whether the result is used for an internal check, calibration or a prescribed trade purpose.

Choose by application, not appearance

Small laboratory balances normally need finer classes and careful handling. Bench, platform and industrial scales may use larger stainless-steel, cast-iron or stackable weights. A weight that is too coarse cannot demonstrate the performance of a fine-resolution balance; buying a finer class than the process needs can add cost without improving the decision.

OIML classes and traceability

OIML class, nominal value and permissible error should be matched to the instrument and test method. Calibration documentation records the measured value and uncertainty at the time of calibration. Keep the certificate with the weight identification, protect weights from dirt and corrosion, and set a recalibration interval based on use, handling and risk.

Before requesting a quotation

• Record the scale capacity, readability or verification interval and model.
• State whether the scale is used for trade, quality control, production or laboratory work.
• List the nominal weights or total loading needed and whether a case or trolley is required.
• Confirm whether a calibration certificate is required and how often the weights will be used.

Useful next steps

Review the dedicated test-weight guide, browse available weight formats, or request a specification and quotation.

Frequently asked questions

Can one test weight check every scale?

No. The mass and class must suit the scale capacity, division and intended test points.

Is a calibration certificate permanent?

No. Handling, wear, contamination and corrosion can change a weight, so intervals should be risk-based.

Request a quotation