A RETIRED airline pilot from west Cornwall has invented one of the most accurate ways of recording hours of sunshine to date.
Alan Blake, 69, from Great Bosullow, created the Blake-Larsen Sunshine Recorder alongside Danish inventor Ole Jul Larsen, 70, after he came up with the concept three years ago.
The recorder, which works by reflecting the sun's rays onto microchips, which then interpret the information electronically, stands out for more accurately taking into account momentary shade.
"I used to be an airline pilot so I have always been interested in it," said Alan.
"It works by reflecting the sun off a mirror onto a light-sensitive chip, data from which is then interpreted by a complex algorithm which tells when the sun is shining.
"It's been invented by two old men in sheds. It's quite exciting – we have spent a lot of time and effort developing it."
Since Alan and Ole came up with their final design last year, Blake-Larsen recorders have sprung up in Denmark, Wales, New Zealand, Venezuela, Italy, France and Holland.
The pair are now looking into the full-scale manufacturing of their device.
Other still widely used ways of recording sunshine include the Campell-Stokes recorder, invented in 1853 and refined in 1879, which involves burning a hole in paper using magnified sunlight. The method has been criticised for not accurately recording sunshine levels at dusk or dawn, subject to the interpretation of the operator.
Alan explained it is difficult to know whether their method is the most accurate as the pair have only had a limited chance to compare with other models.
He said: "It's technically more accurate as even quite small clouds will affect when the sun is shining and compares closely to what a human observer would see."
Readings generated by a Blake-Larsen recorder in Alan's back garden now feature in The Cornishman's monthly weather report.
For more information visit www.sunrecorder.net