Noise detection speed camera trial

Noise detection speed camera trial

Author
Discussion

stevieturbo

16,090 posts

224 months

Thursday 5th May
quotequote all
NMNeil said:
The noise standard since 2016 is 72db
https://www.vehicle-certification-agency.gov.uk/fu...
And all you have to do is buy a db meter and have the officer use it. Not too complicated and the result would be pass or fail and only take a minute or two.
Watching the video you link to in your bio, that Granada would be a fail without question if it was driven on the public roads.
I have been to many events where there is the MSA testing standard applied, and mine is always well below.

And nowhere on that gov website has how it is to be tested. Which is critical because background noise, the environment, distance any angle from the exhaust etc all make a huge huge difference to any dB reading

And as said, the law has not guidance for testing, nor any approved testing meters.

stevieturbo

16,090 posts

224 months

Thursday 5th May
quotequote all
NMNeil said:
The noise standard since 2016 is 72db
https://www.vehicle-certification-agency.gov.uk/fu...
And all you have to do is buy a db meter and have the officer use it. Not too complicated and the result would be pass or fail and only take a minute or two.
Watching the video you link to in your bio, that Granada would be a fail without question if it was driven on the public roads.
And when an ambient background noise level can easily be 70dB....it makes a mockery of a 72dB reading which would be impossible for any roadside test to do with any integrity.

https://www.noisequest.psu.edu/noisebasics-basics....

But again....any such testing to be used for any type of penalty or prosecution would need very strict standards and control, as well as designated/calibrated meters.

30cm could make a huge difference, the angle can make a huge difference, proximity to any objects, the ground, walls etc all make a difference...if you have ever actually used a dB meter for measuring noise from the exhaust area of a car, you would be well aware of this. So there is nothing simple about it

Mr Spoon

1,577 posts

15 months

Friday 6th May
quotequote all
"By 2026 the limit for most new passenger cars will be 68 dB(A)."

so the tyre noise at 70dB makes this pointless.....

NMNeil

3,952 posts

27 months

Friday 6th May
quotequote all
stevieturbo said:
NMNeil said:
The noise standard since 2016 is 72db
https://www.vehicle-certification-agency.gov.uk/fu...
And all you have to do is buy a db meter and have the officer use it. Not too complicated and the result would be pass or fail and only take a minute or two.
Watching the video you link to in your bio, that Granada would be a fail without question if it was driven on the public roads.
And when an ambient background noise level can easily be 70dB....it makes a mockery of a 72dB reading which would be impossible for any roadside test to do with any integrity.

https://www.noisequest.psu.edu/noisebasics-basics....

But again....any such testing to be used for any type of penalty or prosecution would need very strict standards and control, as well as designated/calibrated meters.

30cm could make a huge difference, the angle can make a huge difference, proximity to any objects, the ground, walls etc all make a difference...if you have ever actually used a dB meter for measuring noise from the exhaust area of a car, you would be well aware of this. So there is nothing simple about it
My point had nothing to do with a roadside test, it was that if a car with a loud exhaust triggered the detector the owner would get a notice to take the car to a government department, such as a police station, where the sound level would be measured under controlled conditions and the microphone placed 0.5m from the exhaust tailpipe.

“Stationary Noise Test” means:

(a) in the case of a modified exhaust system, a stationary test as defined in paragraphs 5.2.3.4.2 and 5.2.3.4.3 of Annex I to Directive 70/157/EEC with a noise limit value measured on the dB(A) scale which must not exceed the equivalent stationary value recorded on the approval, certificate of conformity or test report for that vehicle by more than 2dB(A) at 0.5m.

There would be no penalty, it would just fail or pass the test. Failing would be much the same as failing the MOT, you get it fixed. Simple.

https://www.legislation.gov.uk/uksi/2020/818/made


Pitre

3,243 posts

211 months

Friday 6th May
quotequote all
I feel one (or two) of these might be needed..,

Mr Spoon

1,577 posts

15 months

Saturday 7th May
quotequote all
Will they not count as a noise modification?

stevieturbo

16,090 posts

224 months

Saturday 7th May
quotequote all
NMNeil said:
My point had nothing to do with a roadside test, it was that if a car with a loud exhaust triggered the detector the owner would get a notice to take the car to a government department, such as a police station, where the sound level would be measured under controlled conditions and the microphone placed 0.5m from the exhaust tailpipe.

“Stationary Noise Test” means:

(a) in the case of a modified exhaust system, a stationary test as defined in paragraphs 5.2.3.4.2 and 5.2.3.4.3 of Annex I to Directive 70/157/EEC with a noise limit value measured on the dB(A) scale which must not exceed the equivalent stationary value recorded on the approval, certificate of conformity or test report for that vehicle by more than 2dB(A) at 0.5m.

There would be no penalty, it would just fail or pass the test. Failing would be much the same as failing the MOT, you get it fixed. Simple.

https://www.legislation.gov.uk/uksi/2020/818/made
0.5m in what direction ? And under what test conditions ?

It's a nonsense they've been talking about for years. And as everyone knows, trying to make cars silent carries dangers, as people with limited sight have raised serious concerns about their safety as pedestrians.

Obviously balbags with their 5hp vtec's who have a nervous twitch on their right foot is another matter though.

Mr Spoon

1,577 posts

15 months

Saturday 7th May
quotequote all
stevieturbo said:
Obviously balbags with their 5hp vtec's who have a nervous twitch on their right foot is another matter though.
The entitlement through age from your last sentence is the reason youngsters will never want to listen to those who have done exactly the same thing in their youth.

Now now little boys, you're not allowed to have fun as Ive already had it at 19 in my vauxhall nova, took over car parks and drag raced people on the public road. But it was ok back then as it was me doing it.



NMNeil

3,952 posts

27 months

Tuesday 10th May
quotequote all
stevieturbo said:
0.5m in what direction ? And under what test conditions ?
Probably from where the noise comes from, you know, the tailpipe, and the test conditions would be, no or limited background noise and at whatever RPM the original car was tested for type approval.
Not difficult really.

NMNeil

3,952 posts

27 months

Tuesday 10th May
quotequote all
Pitre said:
I feel one (or two) of these might be needed..,
It that a ttmaster 3000?
You know the one that came with a t-shirt saying "Yes that awful noise is from my car, so pay me attention because I'm special"

SturdyHSV

9,034 posts

144 months

Wednesday 11th May
quotequote all
NMNeil said:
Probably from where the noise comes from, you know, the tailpipe, and the test conditions would be, no or limited background noise and at whatever RPM the original car was tested for type approval.
Not difficult really.
Feasibly different in New Mexico, but it isn't the difficulty of getting the reading as such, it's the difficulty of taking the measurement to a legally enforceable standard.

Let's say this is to be done at police stations as you suggest. Where are they going to have an environment with 'no or limited background noise'? You presumably appreciate that 'no or limited background noise' is subjective, and to be legally enforceable would realistically need some sort of definitive value... If one police station is in the countryside with nothing else around, and one is next to a railway line in central London, the background noise levels are going to be very different and as such the test would be inconsistent.

So a defined maximum background noise level would be needed, and thus an area that could reach that level and stay there for the test would be required. That may not be trivial.

The environment it's done in, you'd want it to be an anechoic chamber really, so that you were only measuring the vehicle sound directly. They're not going to outfit every police station with an anechoic chamber big enough for a car.

They also aren't going to be renting the one round the corner from the station, as there won't be any. They also won't be shipping your car to whatever test environment the manufacturers use, due to cost and availability. Equally, unless the environment the police bloke performs the test in meets the specifications of the environment the manufacturer used for type approval, the results between the two will not be comparable in a legal sense, because they weren't tested under the same conditions.

0.5m from the exhaust seems simple, but 0.5m at what angle? If this isn't defined, and one station measures it 0.5m away at 90*, they're going to get very different readings to the other station that measures it at 0.5m directly behind, or 45* above and 45* to the side. So this would need to have a defined acceptable area to test within.

So then they'd need a way to accurately mount the (calibrated) microphone in the correct position. This couldn't just be a nice static rig for consistency, because car exhaust positions vary greatly. This would be expensive, and require training and verification to ensure it is set up correctly.

Should the car be under load? Should they thus have a dyno in the room? That'll produce background noise though. And then they'll need to be trained on how to operate it and secure the car safely. They're expensive too.

You can't just shout "common sense" at something that's going to be legally enforceable.

And on top of that, you will then have another thread on PH somewhere pissing and moaning about how there are no police on the streets doing 'real police work' because they're all off on acoustic engineering training courses to ensure they're qualified to carry out enforceable noise tests on cars.

Oh not to mention the PPE they would need to protect their ears, if it's going to be in a closed room, it'll need to be either very well ventilated (which causes background noise issues) or they'll need breathing apparatus (which causes background noise issues) to avoid inhaling dangerous exhaust gasses and carcinogenic particulates.

Oh and the health and safety training with regards to operating a motor vehicle in a confined environment, especially on those silent dynos they'll have, working in loud environments etc.

Bogsye

338 posts

129 months

Wednesday 11th May
quotequote all
A500leroy said:
my lawnmowers 99db...
2-stroke Leaf blowers are pretty noisy and quite common

fred bloggs

864 posts

177 months

Saturday 14th May
quotequote all
A500leroy said:
my lawnmowers 99db...
You were mowing the lawn when I drove past the noise camera, (sorry, I meant microphone, didn't I )

Id love someone to actually try to look up how loud a 1999 32v commodore ,as my log book states it is ,should actually be.

Edited by fred bloggs on Saturday 14th May 10:13

NMNeil

3,952 posts

27 months

Saturday 14th May
quotequote all
SturdyHSV said:
Feasibly different in New Mexico, but it isn't the difficulty of getting the reading as such, it's the difficulty of taking the measurement to a legally enforceable standard.

Let's say this is to be done at police stations as you suggest. Where are they going to have an environment with 'no or limited background noise'? You presumably appreciate that 'no or limited background noise' is subjective, and to be legally enforceable would realistically need some sort of definitive value... If one police station is in the countryside with nothing else around, and one is next to a railway line in central London, the background noise levels are going to be very different and as such the test would be inconsistent.

So a defined maximum background noise level would be needed, and thus an area that could reach that level and stay there for the test would be required. That may not be trivial.

The environment it's done in, you'd want it to be an anechoic chamber really, so that you were only measuring the vehicle sound directly. They're not going to outfit every police station with an anechoic chamber big enough for a car.

They also aren't going to be renting the one round the corner from the station, as there won't be any. They also won't be shipping your car to whatever test environment the manufacturers use, due to cost and availability. Equally, unless the environment the police bloke performs the test in meets the specifications of the environment the manufacturer used for type approval, the results between the two will not be comparable in a legal sense, because they weren't tested under the same conditions.

0.5m from the exhaust seems simple, but 0.5m at what angle? If this isn't defined, and one station measures it 0.5m away at 90*, they're going to get very different readings to the other station that measures it at 0.5m directly behind, or 45* above and 45* to the side. So this would need to have a defined acceptable area to test within.

So then they'd need a way to accurately mount the (calibrated) microphone in the correct position. This couldn't just be a nice static rig for consistency, because car exhaust positions vary greatly. This would be expensive, and require training and verification to ensure it is set up correctly.

Should the car be under load? Should they thus have a dyno in the room? That'll produce background noise though. And then they'll need to be trained on how to operate it and secure the car safely. They're expensive too.

You can't just shout "common sense" at something that's going to be legally enforceable.

And on top of that, you will then have another thread on PH somewhere pissing and moaning about how there are no police on the streets doing 'real police work' because they're all off on acoustic engineering training courses to ensure they're qualified to carry out enforceable noise tests on cars.

Oh not to mention the PPE they would need to protect their ears, if it's going to be in a closed room, it'll need to be either very well ventilated (which causes background noise issues) or they'll need breathing apparatus (which causes background noise issues) to avoid inhaling dangerous exhaust gasses and carcinogenic particulates.

Oh and the health and safety training with regards to operating a motor vehicle in a confined environment, especially on those silent dynos they'll have, working in loud environments etc.
Obviously adjustments would be needed, but the whole idea is to check the noise level from the tailpipe, and as long as it falls between certain reasonable parameters, all well and good, but if it sounds like a an aircraft taking off, that's a different story and needs to be fixed.
Like this one.
https://www.youtube.com/watch?v=eFjBpwA86sg
What shocks me is they actually want the car to be excessively noisy and probably paid a lot of money to make it so!


DodgyGeezer

31,041 posts

167 months

Saturday 14th May
quotequote all
NMNeil said:
Obviously adjustments would be needed, but the whole idea is to check the noise level from the tailpipe, and as long as it falls between certain reasonable parameters, all well and good, but if it sounds like a an aircraft taking off, that's a different story and needs to be fixed.
Like this one.
https://www.youtube.com/watch?v=eFjBpwA86sg
What shocks me is they actually want the car to be excessively noisy and probably paid a lot of money to make it so!
just to make you feel better - my old Camaro SS was louder hehe