Hi!

After calibration, how can I get the residual errors? These errors are mixed together, is it hard or impossible to separate them by simply connecting some standards?

Maybe we can measure residual errors in time domain, but I donâ€™t know if the method is available.

After calibration, how can I get the residual errors? These errors are mixed together, is it hard or impossible to separate them by simply connecting some standards?

Maybe we can measure residual errors in time domain, but I donâ€™t know if the method is available.

One way of finding out the residual errors is the Ripple Technique.

This involves connecting and air line to the test port after calibration and connecting a well matched load and a short circuit to the end of the line to get the residual directivity and source match respectively.

When you attach the load you will get a 'ripple' on the trace. (see attached image)

The maximum directivity is determined by taking the maximum adjacent peak to trough amplitude and dividing by 2.

(e.g. the attached has a directivity ~6.5 mUnits)

The source match follows the same procedure but by using the short circuit.

NPL have lots of reports in the area http://www.npl.co.uk/electromagnetic/cl ... tions.html