I've noticed that noise testing on trackdays is becoming a bit of an issue these days, there was even a small article about it in last months Racer. If your bike fails, that's it, you're not allowed out on track. I know that Maxim was right on the limit at 104.9dB (limit's was 105dB that day).
It got me thinking,.....failing could be a costly exercise so i looked up what the ACU had to say about it all and realized that the guy doing the testing at Brands that day didn't appear to know what he was doing.
So here goes..know your rights
1. The microphone should be held 50cm away from the end can, at an angle of 45degrees. Each can is to be tested individually.
2. With the bike in neutral the engine should be held at 7000 RPM (for a 2 cylinder 2 stroke) whilst the test is carried out.
3. The meter reading should be rounded down, so 104.9dB = 104dB.
4. For temperatures below 10 degrees deduct 1dB
5. 'Post race' or if your pulled in for a test during a track session there must be a tolerance of 3dB.
6. If your bike fails, it can be retested 'several times'?
7. The testing apparatus must be to international standard IEC 651 Type 1 or Type 2.
Now I'm not sure if any of this will be of use, or even if arguing with the trackday organiser that they haven't conducted the test correctly will allow you to ride, but it might help in some small way.