“Has anyone on here that has been done for speeding ever asked, has the speed gun / or any other device been calibrated, & when also the paper work to show…”
Well, if they have, TWR, they will probably tell anybody else considering doing so not to bother. It is an urban myth which says all you have to do is to ask for this information and the prosecution will go away. It won’t, and you should remember this:
The information will not be routinely provided and will certainly not be available to enable the driver to decide whether or not to accept a Fixed Penalty Offer. He will have to opt for a court appearance where he will have to plead Not Guilty. If he is to use the “inadequately calibrated machine” as his defence the onus will fall on him to cast sufficient doubt in the Magistrates’ minds so that they cannot be sure of the machine’s accuracy. More than this, to avoid conviction he will have to convince them that the machine is so inaccurate that, not only did it record the speed inaccurately but that it did so to such a degree that there is doubt that the speed limit was exceeded at all. (e.g. if the speed alleged is 85mph he will have to demonstrate sufficient doubt that it was out by 15mph). There is no statutory requirement to calibrate speed guns or cameras at any particular intervals and the defence, such that it is, is rarely successful.