Case Law Regarding External Testing Of Radar Unit

Is there any case law regarding external testing of a radar unit? I know there has been some for LIDAR. In older days, a tuning fork was used but no longer? or is it dependent upon the make and model whether or nor an external test is done on the unit?

Thanks in advance.

Paul

It needs to be tested "as per the manufacturers instructions", which depends on the model. This is why some people request the manuals for the unit that was used.