That is done as per the unit standard (usually annual, I think) by an outside electronics firm such as Pylon Electronics. If a very specific tuning fork is made in such a way as to induce, say, a displayed reading of forty-five Km/Hr, then the use of said fork can be an external test of a ‘Doppler Traffic Radar.’ So, what of tuning forks? Well some genius struck upon the notion that a tuning fork can, as it oscillates back & forth at 90 degrees to the ‘beam,’ induce a very specific Doppler shift for the unit to measure. The unit represents what it is measuring (a Doppler shift) w/ an audible tone that the cop hears as he observes the traffic stream. That change in frequency is commensurate to the speed of a moving vehicle (closing vehicle compresses the wave minutely in accordance w/ Doppler’s Principal & a vehicle moving away lengthens the wavelength). It will determine if this beam’s known frequency has been changed to any measurable extent. If the police vehicle is not moving (stationary mode) then what the device does is ‘listen’ for returned or reflected instances of this emitted ‘beam’. The device emits a microwave ‘beam’ (no real radar involved) down the road. First off, this is so stunned it’s painful: “…the vibration of the fork mimicked the vibration of a car in motion…” First off, with the exception of an old Mercury Lynx I had, vehicles do not ‘vibrate’ down the road. It may be inconvenient to use the tuning fork but it will either validate the tickets issued during the shift or dictate the faulty unit be sent out for repair rather than waste the day issuing invalid tickets. Knowing the radar unit is working properly at the beginning of the shift, end of the shift and probably through the duration of the shift is in the best interest of all involved. Can the internal self test mode be depended on if the unit is faulty and what prevents the internal self test circuitry from being faulty? My understanding is the tuning fork is to be used before the first ticket is issued in the work shift and after the last ticket of the shift is issued. How robust or delicate these units are is part of the question and the reason for the external test in the first place. The radar is a precision testing instrument. It is not used to calibrate but to check the calibration. The use of a tuning fork is an external test to confirm or refute the accuracy of the radar unit. Check here for the rest of CBC’s story, including some quotes from experts on traffic duty who think the move to abandoning the tuning fork test is a mistake. Why does the RCMP think it necessary to calibrate their equipment, and the OPP doesn’t? How often does this equipment actually require recalibration? Have people been falsely convicted of speeding, and if so, how many?ĬBC says Decatur Electronics did not provide them with a copy of the manual used by Canadian police departments. The manufacturer decided the test wasn’t necessary anyway, and stopped including it in the manuals after saying it wasn’t legally necessary in Canada, he said.Īlong with the troubling idea of traffic cops lying in court, CBC’s discoveries raise some other interesting questions. He said that came partly because officers were saying court they had tested the equipment at the start of their shift, before issuing tickets - but sometimes they hadn’t. The CBC says a former OPP speeding specialist now says that’s changed. Originally, the manuals for Decatur Electronics, a manufacturer of the equipment for the OPP, asked officers to test their equipment with a tuning fork the vibration of the fork mimicked the vibration of a car in motion, and allowed officers to ensure their radar guns had accurate readings. In the past, those departments used a tuning fork to determine if the device was still accurate other departments across Canada still continue that practice, including RCMP detachments and the Sûreté du Quebec. Differences in radar speed detection calibration across the country are raising some doubts about the validity of the process, says a report by CBC.Īccording to the CBC, the OPP and the Regina Police Service have both indicated they no longer test their radar speed detection equipment for proper tuning at the start of each shift.
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