We have a received a request under the Freedom of Information Act 2000 for the following:
“The Home office sent me the above mentioned publication in the hope that I could discover what criterion the Home office requires for calibration / type approval of speed detection equipment.
My specific enquiry is centred around the LTI 20-20 speed scope, and as this falls into the category of hand held optical devices, the Home office thought that publication 18/98 would be of use to me. I have read the publication carefully and I have several questions that I hope you will be able to answer.
Section 5 specifically deals with hand held optical devices.
5.1.1 states that All in-built test routines shall be run, and the results recorded.
(I am assuming by this you mean that all tests should pass. Forgive me if that sounds silly, but it doesn’t actually state that they have to pass)
Question 1, Do all in-built test routines during calibration have to pass?
Sections 5.1.2 through 5.1.5 describe specific tests that are required for calibration but does not include the optical power output test. The optical power output would directly affect (amongst other things) Signal to Noise ratios. The manufacturers deem this parameter important and have specified a tight tolerance of +/- 15%.
Question 2, Why is there no mention of the optical power output test?
Question 3, Is this test important or is it assumed to be covered by section 5.1.1?
Question 4, Will a device maintain type approval if it fails to meet the manufacturers specified tolerances?”
We released the following information on 9 May 2007.