On Tue, 20 Mar 2007, cmh856@aol.com wrote:
That seems a bit sketchy, but as long as the laser is really a 20mw unit, I'll accept an "eyewash" label.
Does anyone know how laser power levels are measured? In the absence of a reliable means of measuring "light output power", it'd be interesting to compare the electrical power consumption of the 20mw models against the 5mw models. I don't know if laser diode efficiency varies by a factor of four, but if the 20mw laser consumes less than four times the power consumed by an average 5mw laser, I'd be very suspicious of claims that the 20mw laser is really putting out four times more laser light power. It should be a simple test: first measure the battery voltage and then put an ammeter inline with the batteries to see how much current flows when the device is switched on. If you want to add another dimension to your comparison tests but don't have a volt/ammeter, I'll bring one. :-) Chris