The establishment of a South African national measuring standard for force

This article describes the tests made on the force comparator measurement System.

The availability of an accurate force standard is an important facility for both science and industry. Deadweight machines can be employed to provide very accurate Standards, but they have a very high capital cost. Ort the other hand force comparator machines, where the force transducer under test is compared with a reference force transducer in a testing machine, represent a more economical alternative to the expensive deadweight machines. However, careful design is essential in the dimen-sioning of the testing machine and the selection of a suitable reference transducer. The National Standards and Metrology Division at the National Physical Research Laboratory in South Africa selected the HBM C4 range of force transducers for use as reference transducers. A DMP 39 Precision Digital Measuring Unit was used to amplify the transducer signals.