It is necessary also to perform comparisons between the force calibration machine and an appropriate national force standard machine using high quality transfer standards – the procedure for this work may be as described in section 5.2 but the results need to be analysed in a different way, as it is a comparison exercise rather than a calibration. The analysis needs to demonstrate whether or not the results from the two machines are metrologically compatible – one method
for assessing this is described in [4] and involves determining whether or not the En values calculated across the range of applied force exceed unity.