Re: California Laws on Proper Calibration of Radar Units and Tuning Forks
Since you are asking a general question (without being specific as to which VC section you were cited for), I will give you a general answer where you can start your research...
The only specific "legal" requirement for radar calibration (that I am aware of) is included in CVC section 40802(c)(1)(D) which establishes the prosecutions burden to prove that "The radar, laser, or other electronic device used to measure the speed of the accused meets or exceeds the minimal operational standards of the National Traffic Highway Safety Administration, and has been calibrated within the three years prior to the date of the alleged violation by an independent certified laser or radar repair and testing or calibration facility" when prosecuting a Prima Facie speed limit case.
Anything above and beyond that will more than likely be part of an inter-departmental policy for each law enforcement agency... My guess is that you will not get too far requesting any of it.
You're free to search through the National Traffic Highway Safety Administration website in hopes that you can establish what their minimal operational standards are... Although with as broad as the legal requirements (which i outlined above) are, I highly doubt that you can successfully turn any findings there into a viable "legal argument" or a "plausible defense" that will work for you in court.
Based on the numerous times I have heard officers testify during speeding cases, and while they may make reference to a daily test for their radar equipment, I am yet to hear of anyone successfully arguing that the case should be dismissed based on the lack of a "tuning fork" test or in the absence of related testimony.
You're free to do the work that you set out to do, or you can post more information about your citation so that we can all find out if you have any other possible defenses that you might be able to utilize.
I am right 97% of the time... Who cares about the other 4%!