IEC 60601-2-54:2009 Accuracy of CURRENT TIME PRODUCT

[FranK_SP]

Dear All,

In the following point of the standard IEC 60601-2-54:2009-> 203.6.4.3.104.6 Accuracy of CURRENT TIME PRODUCT, the acceptance criteria is ± (10 % + 0,2 mAs).

Does anybody know where +0,2mAs comes from??? Could be related to any kind of physics effect or deviation regarding measurement equipment???

Thank you!!

 

[Peter Selvey]

A good accuracy specification should be in the form of ±X% ±Y where Y is absolute value of the measured parameter. This is for measurements at the low end of a range where keeping ±X% would be meaningless relative to the limit and hence a waste of resources.

For example, consider a limit of 100µA. The standard might say the measurement should be accurate to ±5%. However, if a particular device under test had only 6µA, then measuring 6µA to ±5% accuracy could be technically difficult and also meaningless since it is obviously well below the allowable limit. So a better accuracy specification would be say ±3% ±2µA (== ±5% at the allowable limit).

 

[FranK_SP]

Hi Peter,
Thank you for your answer!.