Advice on Safety

[Kukee]

Hey Guys,

I am going to be using my Laser for the first time at a gig, but I would like to clarify some safety stuff. The laser is RGY (70mw Green (532nM) and 130mW Red (650nM) DPSS laser.

I understand that it should be 3m high, and obviously not pointing downwards to the audience. Is the 3m also for the beam? The unit will make laser tunnels and wave sweeps, so having the beam not going lower than 3m would mean pointing the unit 45 degress upwards towards the ceiling, is this correct?

Thanks for your advice

Neil

[Jem]

Hi Neil

Take a look at this document (HSG95)...

http://www.hse.gov.uk/pubns/priced/hsg95.pdf

This pretty much tells you everything you need to know about safety for public shows. and is a good place to start. There are other documents that you need to be familiar with as well

Pay particular attention to paragraph 33 in HSG95 which deals with your question...

33.
Supervised installations should be designed so that hazardous emissions are not accessible at any point less than 3 m above and 2.5 m laterally from any location at which a member of the audience or public may gain access during a display (see Figures 4 and 5). For unsupervised installations, it is good practice to increase the vertical separation distance to 6 m.

Obviously if you intend to audience scan it's a whole different ball game and you'd better be ready for some measurements and calculations. Incidentally, have you prepared your method statement, safety policy and risk assessment and submitted them to the local authority for approval, also, have you got yourself some insurance... Oh, and I almost forgot the laser safety signs at all entrances to the venue

Cheers

Jem

[Kukee]

Thanks for that, I will take a read. So when you are at venues and bars and they have the laser going and you can stand in the tunnel, that is just irresponsible or the venue?

[Jem]

Thanks for that, I will take a read. So when you are at venues and bars and they have the laser going and you can stand in the tunnel, that is just irresponsible or the venue?

Err... Well, if they've done it 'properly' they will have done the MPE calculations and it will have been approved by the local authority as a 'safe' show for audience scanning with all the beams being below the MPE.

On the other hand maybe they've bought a Chinese laser on Ebay and just screwed it to the ceiling

Jem

[Kukee]

Thanks for the advice, I think I would rather be safe and either not use the laser if a small venue or point it at the correct angle.

[buffo]

Kukee;

If you want to be 100% safe, then yeah - point the projector towards the ceiling so that no beams can get into the audience. (That is, aim the projector such that the beams *always* stay at least 3 meters off the floor.) That's the way we have to do it here in the US. (Well, we usually don't tip the projector, we just install a hard mask that stops the beams from exiting the projector below the horizontal, then we mount the projector 3 meters high and adjust the scan pattern upward in the software so it clears the mask.)

As Jeremy said, if you want to do audience scanning, then you've got some homework to do first. It can be done safely, but it requires that you fill out some paperwork. You'll also need to buy a calibrated power meter and take some measurements, and then work through a few calculations...

Adam

[mccarrot]

With the simplified approach you don't have to calculate anymore, only measure.

If you measue a static beam at less then 10mw/cm2 at the closest point to the audience you are ok when the show is scanning

[White-Light]

With the simplified approach you don't have to calculate anymore, only measure.

If you measue a static beam at less then 10mw/cm2 at the closest point to the audience you are ok when the show is scanning

You do need an oscilloscope to check the minimum scanner speed on all the patterns as there is a minimum scanner velocity required to use the simple method. If in any pattern the scanner drops below the minimum velocity you're screwed so far as using the simple method is concerned.

[mccarrot]

More info please, I have never heard this before, can you tell me on which page to look on the simplified approach document?

http://www.laserist.org/files/audien...rview_2pt1.pdf

[pelosh]

With 200mW laser I wouldn't care much about .....

Ehm..sorry!

Of course, everything must be done according to tough regulations. MPE, assessment, local authorities and all that crap.

Unfortunately all that crap can become VERY usefull if someone gets blinded by something else (i.e. laser pointer) before, during or after your event...because if it happens and you have no paperwork to prove your show was safe you screwed!