How to make sure you're not testing too often or too little?
Daily routine testing of laboratory balances at multiple points in the operating weighing range can take a great deal of time and effort, and may not even provide any meaningful metrological information. The recommended frequency of routine testing for any given balance depends on the risk and consequences of inaccurate results for the business, and/or health risks for users, combined with the ability to trace back errors. The risk of inaccurate results can be assessed by answering the following questions:
- Business impact: What is the impact of wrong or inaccurate weighing results on your business process? Consider loss of material and time, out of specification results, rework, production downtime, fines, product recalls, unhappy customers, loss of reputation, etc.
- Consumer impact: What is the impact of wrong or inaccurate weighing results on people, animals or the environment?
- Probability of detection: Is there a chance of detecting a wrong or inaccurate weighing result immediately and easily?
Discover in the guide what is really essential for testing your laboratory balance and get tips on designing test frequencies that are reasonable and appropriate.
Test methods, warning and control limits
Routine tests may include sensitivity, repeatability and eccentricity tests using appropriate calibrated test weights. Tolerances or warning and control limits depend on the weighing tolerance for the process in question. Warning limits indicate when a device is nearing an out-of-specification condition. Control limits alert you when the device is no longer deemed fit for purpose.
Routine testing of lab balances between scheduled calibrations helps to maintain accuracy by ensuring early detection of non-compliance with weighing process requirements so that corrective action can be taken in a timely manner.