Derbyshire GATSO camera modules moved from site to site...
Discussion
First the negative PR for Derbyshire:
Derbyshire Safety Camera partnership have confirmed that Derbyshire Constabulary do NOT prosecute for 30mph+10%+2mph, OR 40mph+10%+2mph, but DO prosecute for 50mph+10%+2mph!
Given that GATSO cameras are only certified by the Home Office to be accurate to within +/-2mph at speeds under 60mph, that means that Derbyshire are prosecuting me for 55mph on an empty 50mph dual carriageway, early on a Sunday evening.
Now the nitty gritty of the moving modules in Derbyshire:
Has anyone else come across the circumstances where GATSO camera and radar modules (but particularly camera modules) are being moved from camera site to camera site, in between calibration certificates. In essence, the calibration is carried out away from the camera cabinet / site, the location in which the camera module is used then changing, from site to site, before it is recalibrated.
1. It would appear that no calibration / certification of resistance / voltage regulation is being carried out at the cabinets when the module is inserted in the cabinet, or is there calibration in this area already?
2. Has anyone ever had evidence to substantiate that voltage regulation and cabinet circuit resistance has been checked during this process?
3. Does anyone know if the modules have independent voltage regulation, given that 'street power supplies' are notoriously 'dirty'?
3. Does the Home Office certification / Gatsometer calibration certificate for GATSO cameras cover them for this type of use on multiple sites?
4. Has anyone come across a suitable 'expert' winess in this area?
PLEASE stay on topic in your response...
Derbyshire Safety Camera partnership have confirmed that Derbyshire Constabulary do NOT prosecute for 30mph+10%+2mph, OR 40mph+10%+2mph, but DO prosecute for 50mph+10%+2mph!
Given that GATSO cameras are only certified by the Home Office to be accurate to within +/-2mph at speeds under 60mph, that means that Derbyshire are prosecuting me for 55mph on an empty 50mph dual carriageway, early on a Sunday evening.
Now the nitty gritty of the moving modules in Derbyshire:
Has anyone else come across the circumstances where GATSO camera and radar modules (but particularly camera modules) are being moved from camera site to camera site, in between calibration certificates. In essence, the calibration is carried out away from the camera cabinet / site, the location in which the camera module is used then changing, from site to site, before it is recalibrated.
1. It would appear that no calibration / certification of resistance / voltage regulation is being carried out at the cabinets when the module is inserted in the cabinet, or is there calibration in this area already?
2. Has anyone ever had evidence to substantiate that voltage regulation and cabinet circuit resistance has been checked during this process?
3. Does anyone know if the modules have independent voltage regulation, given that 'street power supplies' are notoriously 'dirty'?
3. Does the Home Office certification / Gatsometer calibration certificate for GATSO cameras cover them for this type of use on multiple sites?
4. Has anyone come across a suitable 'expert' winess in this area?
PLEASE stay on topic in your response...
Please stay on topic - the last response doesn't seem to address any of the four questions above.
Anyone seen the certification from the Home Office for camera modules when moved from site to site?
Anyone have evidence of voltage regulation / resistance checks during the relocation process?
Anyone seen the certification from the Home Office for camera modules when moved from site to site?
Anyone have evidence of voltage regulation / resistance checks during the relocation process?
Edited by ramtec on Saturday 14th July 19:13
ramtec said:
So, for all the volume of 'chat' on here (particularly from the pro-authoritarian anoraks), apparently no one has yet challenged on the basis of GATSO site voltage regulation and resistance...
Wow!
Perhaps people just prefer not to answer your questions because of the manner in which you ask them. Wow!
No, sorry, don't see anything in the original post that could possibly offend anyone... unless of course they had something to lose on the subject of voltage regulation / resistance calibration...
"Stay on topic" is all about making the board useful. Fluffy clouds won't be indulged in court, so let's stick to the point. If you can't have a focussed, adult discussion, suggest you try MSN...
The surprised comment, that no one has challenged on this area yet, is quite genuine.
"Stay on topic" is all about making the board useful. Fluffy clouds won't be indulged in court, so let's stick to the point. If you can't have a focussed, adult discussion, suggest you try MSN...
The surprised comment, that no one has challenged on this area yet, is quite genuine.
Edited by ramtec on Sunday 15th July 19:31
Edited by ramtec on Sunday 15th July 19:33
gatso equipment uses SMPSU's - switch mode power suply units.
SMPSU's couldn't give a flying s***e what the input voltage is like, as long as it's somewhere between 55v and 400v, with a brown out tollerence interval of (I think) at least 2 seconds. Loop resistance is also irrelevent, as long as it can supply the required VA, which is only about 200. Basically the loop resistance would have to be greater than about 40-50 ohms to affect the operation of the camera.
the output will be an absolutely rock solid 5v, 12v and -12v. Similar to a computer power supply.
SMPSU's couldn't give a flying s***e what the input voltage is like, as long as it's somewhere between 55v and 400v, with a brown out tollerence interval of (I think) at least 2 seconds. Loop resistance is also irrelevent, as long as it can supply the required VA, which is only about 200. Basically the loop resistance would have to be greater than about 40-50 ohms to affect the operation of the camera.
the output will be an absolutely rock solid 5v, 12v and -12v. Similar to a computer power supply.
ramtec said:
Great stuff Bryan, thank you!
You ever checked your 'rock solid' computer power output lately? Not, perhaps that rock solid, after all...
Proving that mains voltage (for which the cameras are type approved) fluctuates is probably the easy bit.You ever checked your 'rock solid' computer power output lately? Not, perhaps that rock solid, after all...
IMO, proving that these fluctuations adversely affect the accuracy or reliability of the camera is something entirely different.
Edited by SS2. on Tuesday 17th July 12:49
ramtec said:
So, why do camera modules need recalibrating?
The official line is 'Speedmeters (cameras) are calibrated annually and a certificate produced which provides reassurance to the courts that the device is still measuring accurately using instruments calibrated to national standards.'bryan35 said:
gatso equipment uses SMPSU's - switch mode power suply units.
SMPSU's couldn't give a flying s***e what the input voltage is like, as long as it's somewhere between 55v and 400v, with a brown out tollerence interval of (I think) at least 2 seconds. Loop resistance is also irrelevent, as long as it can supply the required VA, which is only about 200. Basically the loop resistance would have to be greater than about 40-50 ohms to affect the operation of the camera.
the output will be an absolutely rock solid 5v, 12v and -12v. Similar to a computer power supply.
Bryan! You're a genious! To think, I nearly let that get away! No one CHECKS the specification is within the limits you espouse!!!! Derbyshire Constabulary, under interview earlier this week admitted that there's NO maintenance schedule for the cabinet, not even basic Health & Safety stuff, never mind voltage regulation and reisistance checks. Not since its installation in 1997. Nor does there appear to be any type approval for calibration in the Netherlands, and then continual movement from site to site, in between calibration. So, no need to question the accuracy of the camera module per se, but every reason to request disclosure of the maintenance and calibration schedule for voltage and resistance at the cabinet...SMPSU's couldn't give a flying s***e what the input voltage is like, as long as it's somewhere between 55v and 400v, with a brown out tollerence interval of (I think) at least 2 seconds. Loop resistance is also irrelevent, as long as it can supply the required VA, which is only about 200. Basically the loop resistance would have to be greater than about 40-50 ohms to affect the operation of the camera.
the output will be an absolutely rock solid 5v, 12v and -12v. Similar to a computer power supply.
I did declare my commercial interest on another thread, but just in case - McLean Productions is researching a production around 'Expert Evidence'.
Edited by ramtec on Saturday 21st July 16:37
Edited by ramtec on Saturday 21st July 16:37
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