Saved by Blunt instrument
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DETECTIVE work by David Blunt, Perkins Engines' instrument project engineer, is saving the company the need each month to send away exhaust-smoke meters for calibration to meet the US Federal authorities' stringent regulations on emissions.
He tracked down a 60-year-old Bell prover, originally used to calibrate domestic gas meters with remarkable accuracy, in a Leicester warehouse and bought it for £250, which was probably less even than its scrap value.
With only photos to guide him, he restored the prover and arranged its complicated ropes, pulleys and counterbalancing weights.
The result is a device that measure air and exhaust gases within a degree of accuracy of 0.2 per cent, which is a pretty sharp performance for a blunt instrument.