Hi, I currently have a black body calibration source which I use for work. It works great, I can calibrate all the IR thermometers just fine, however it isn't a simple quick "check". The IR thermometers are the ratio type in that they measure two wavelengths and using the ratio it can work out the temperature. I was wondering if it would be possible to use something like two lasers at the detector wavelengths to simulate this for day to day checking purposes? This would be to pick up on damage that may have occurred to the optical fibre leads or lenses from the harsh industrial environment they operate in. Accuracy would not be critical, just stability as they would be checked against a laboratory IR thermometer which would not be exposed to this environment. LEDs or any other light source would be fine, I was thinking even incandescent light bulb, provided I could get a filament large enough. On the topic of incandescent light, since the filament is so small and hard to "aim" at, what mechanisms are possible for getting a relatively even spot of light to aim at?