|2.5 lb weight on twine hanging from the tripod as low to the ground as possible|
|A simple loop of string for this 2.5 lb weight|
|On flat ground, the weight hangs just above the grass|
Next up, I was super pumped when this green laser
However, the safety label on the laser does say that the max output is <100mW, that it's a class III laser product, and that it complies with 21CFR (what the heck is that?). So I looked it up:
21 CFR 1040.11(b) and 1040.11(c), limit surveying, leveling, and alignment, and demonstration laser products to Class IIIa. This means that pointers are limited to 5 milliwatts output power in the visible wavelength range from 400 to 710 nanometers. There are also limits for any invisible wavelengths and for short pulses. Pointers may not exceed the accessible emission limits of CDRH Class IIIa or IEC1 Class 3R. (FDA.gov)Well now I'm confused. The laser was marketed as 100mW but the label says <100mW. It says it complies with 21CFR, but the laser also includes the words "laser pointer" on the metal clip. It states that it is Class III but not whether it is IIIa or IIIb. So which is it?
|Is this label illegal for a "pointer" stronger than 5mW?|
Either way, this is a potentially dangerous laser product that is capable of lighting a match from 30 cm range, blinding pilots, and causing all kinds of legal problems with the FAA. Let's just say I plan to use it sparingly to point out constellations. I've also read some good tips online, such as always keeping the laser moving and circling stars rather than pointing right at them just in case they are aircraft.
You might also check out this article from Universe Today on the Hazards of Green Laser Pointers, and Some Pointers on the Use of Laser Pointers from Sky & Telescope. Also, I'm not sure if it's the law here, but the Astronomical Society of South Australia recommends carrying your astronomical society membership card with you to show authorities that you are using your laser for educational purposes.