When is Legal-for-Trade required?
Anytime weight is used to determine a price or an award is given.
What is required to be Legal-for-Trade?
- The scale needs to be appropriate for the application. Minimum amount weighed should be more than 50 graduations. Example: Scale configuration of 30 lb x 0.01 lb, usable range would be 0.50 lb to 30 lb.
- The scale needs to have an NTEP certificate. This means the scale manufacturer sent the scale to a laboratory for testing and it was determined to be stable over time and temperature changes.
- The scale needs to be calibrated in the location where it will be used. Gravity varies with altitude and latitude, so scales rarely weigh correctly when they arrive. Note: Weights and measures will not calibrate your scale.
- The scale needs to be registered and approved for use by the local authority. Typically this is the Weights and Measures Division of the State Department of Agriculture.
Why should scales have regular service?
The best answer is loss prevention. To most people a 1% error doesn't sound like much. But a 1% loss in revenue over weeks or months can be a lot. Or a 1% error in a chemical mixture can make a huge difference. Having an accurate scale requires regular effort. And for most businesses, getting scales tested and calibrated every six months is cheap insurance.