Learn How to Select the Correct Test Weights and Weight Class

Routine testing of balances and scales between scheduled calibrations helps to detect non-conformance with weighing process requirements early to maintain accuracy. However, for reliable testing, it is important to select the correct test weights while ensuring adequate testing frequency, test methods/SOPs, warning/control limits, and user training.

To help you select test weights, Mettler-Toledo offers a free service called GWP® Recommendation. Using the scientific principles of Good Weighing Practice^TM, the recommendation relies on your answers to a quick series of questions including the maximum capacity of the weighing device, the weighing tolerance, the safety factor, and environmental conditions. Based on this input, your GWP® Recommendation will specify the correct test weights to check the performance of your device.

According to USP chapter 41 and Mettler-Toledo Good Weighing Practice™ (GWP®), performance tests should be done at <5% of the balance capacity for repeatability testing and at <100 % of the balance capacity for sensitivity and eccentricity testing. To meet these requirements more easily and eliminate the cost of maintaining a larger weight set, Mettler-Toledo offers CarePacs.

The comprehensive CarePac solution offer you only the essential tools you need to put balance routine testing into practice. They provide you with two carefully selected test weights, a calibration certificate, and accessories including tweezers and gloves for safe, professional weight handling.

CarePac sets, available in three box sizes with twelve combinations different nominal values, support the testing of balances up to 8 kg and the verification of tolerances down to 0.03%. A third, customer-specific test weight can be added when required; however, two weights generally allow you to obtain trustworthy results.

Mettler-Toledo test weights themselves are available as OIML or ASTM single weights or weight sets from 50 µg to 5000 kg. Made of the finest quality austenitic steel to offer the highest resistance to corrosion, all test weights are supplied in a robust, easy-to-clean case to protect the each weight’s integrity.

When required, test weights are delivered with a calibration certificate from a Mettler-Toledo calibration laboratory that is produced in accordance with ISO / IEC 17025 requirements to fulfil metrological traceability requirements.

Contact Mettler-Toledo for a free GWP® Recommendation for weight selection, or learn more about how their high-quality test weights and CarePacs can help ensure ongoing accuracy in your weighing processes.

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