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Feb 02, 2008 11:31 am
Feb 02, 2008 11:31 am
Subject: Re: Speedo / rev counter instrument o'haul
Hello everybody,
I would like to add to Alan’s suggestion of just moving the pointer. This was on my mind when I mentioned doing the calibration run to produce the error curve. The error will not be linear and if you follow Alan’s suggestion, you could have the speedo/rev counter running 100% accurate at one point. This ought to be at the most critical part of the range – say 50 mph or 2500 rpm. Beyond the, you will have established the error and will just have to live with it. Of course there is enormous fun to be had ‘on you kitchen table’ playing with the spring tension as well….
When I repair temperature gauges, once re-filled with ether, I use the ‘Alan Elliot method’ for calibration. Using a digital thermometer and an electric kettle I move the pointer to read dead right at about 90 degrees c. This is ‘good enough’ to warn me that something has gone wrong with the cooling and who cares whether the temperature gauge indicates 80 degrees when the car actually runs at 76 degrees – or vice versa for that matter.
Cheers
Colin Mallett
Hello everybody,
I would like to add to Alan’s suggestion of just moving the pointer. This was on my mind when I mentioned doing the calibration run to produce the error curve. The error will not be linear and if you follow Alan’s suggestion, you could have the speedo/rev counter running 100% accurate at one point. This ought to be at the most critical part of the range – say 50 mph or 2500 rpm. Beyond the, you will have established the error and will just have to live with it. Of course there is enormous fun to be had ‘on you kitchen table’ playing with the spring tension as well….
When I repair temperature gauges, once re-filled with ether, I use the ‘Alan Elliot method’ for calibration. Using a digital thermometer and an electric kettle I move the pointer to read dead right at about 90 degrees c. This is ‘good enough’ to warn me that something has gone wrong with the cooling and who cares whether the temperature gauge indicates 80 degrees when the car actually runs at 76 degrees – or vice versa for that matter.
Cheers
Colin Mallett