Ares ii - some help please

[sc0ttdj]

Hi folks,
this is my first post on here, so take it easy

My question is im new to owning lasers, so i bought two of them to
enhance the lighting while i dj. i'd like to know the safety aspect of them, do i need to do anything special to make sure there safe?

i work with two real high powered lasers all day one being a 2.2kw one for burning wood and metal.so i know just how wrong these can go!

The lasers i bought are an Ares ii and this one, not a clue what it is apart from it was cheap http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWNX:IT

Any advice and guidance would be great

Im in the uk, i noticed a lot of you guys are in the states, so im sure
the laws may be different

thanks

[colouredmirrorball]

In order to be safe, you need to measure the power with a power meter. You can buy a cheap one for $100 I think. There is some info here in the forum about how it can be done.
The first thing you need to know is the mW/cm². If you have a good power meter, there might be a mW/cm² option in it. The $100-versions don't, so you need this formula:
I = p/(π[d/20]2)
I is mW/cm², p is the measured power, π is pi and d is the diameter of the round spot in mm.
You must test the power at the first spot where the public can look into the beams.
The MPE or Maximum Permissable Exposure is 10 mW/cm². That isn't very bright. This is why there is a new standard: 100 mW/cm² or 10xMPE. This is more or less safe with high speed scanners. Your scanners are stepper motors. This means the MPE for your laser will be a lot less. With your unit, I'd go for 10 mW/cm².
What if you have measured a level that is higher than the MPE? There are several ways of diminuish it. First of all you can of course turn the power of your laser down. This option is of course not very popular and I doubt if it's possible with your unit.
You could also enlarge the beam width. This drastically lowers the level.
Distance has a huge factor too: the further, the more the beam is spread out, the more your show is safe.

Good luck calculating!

[sc0ttdj]

I'll have to find the guide, most of what you said just flew straight over my head.

Thanks for the reply though

[colouredmirrorball]

Yeah, I'll never become a good math teacher .
Others might explain it better, I'm no expert.