How about transcribing it to a Google Docs spreadsheet? It'd work on anything with a browser then.
Senior Member
How about transcribing it to a Google Docs spreadsheet? It'd work on anything with a browser then.
Senior Member
That would work for the raw spreadsheet, not sure about the text and links though. I'll give it a try.Originally Posted by heroic
Doc's website
The Health and Safety Act 1971
Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.
Senior Member
Very nice doc!!! good job!
some remarks.
- Before putting out the unmodulated!!! static beam dail down the power down first and turn up the power slowly while measuring the power
- your meter needs to be a very sensitive meter in the mW range. DIY meters like Die4thing and laserbee are not sensitive enough to measure MPE levels (1MPE = 3.6mW with 7mm aperture)
- 10x MPE is taking a (acceptable) risk, but is not 100% safe!
- You need to have a working scanfail.
- if you have turned up the power to you preffered MPE level you can use this value in you Beam Attenuation Map
- you need to keep beams moving
- if you have turned up the power to you preffered MPE level you can use this value in you Beam Attenuation Map
Senior Member
Senior Member
can someone explain to me the "Iris diameter" parameter? Is it the beam diameter at the closest point where it can meet the eye? Thanks
Senior Member
7mm is the accepted average diameter of the human pupil at the likely ambient light levels one would expect at a laser show.
Therefore if we measure the laser energy falling on to the calorie meter sensor through a 7mm diameter apperture (38.48mm^2 area), we can then calculate the power density in mW/cm^2
Doc's website
The Health and Safety Act 1971
Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.
Senior Member
you need to have a fixed aperure in front of the detector to calculate mw/cm2
The iris is the aperture size in front of your detector.
this can be a black plastic or steel cover with a 7mm hole in it.
Senior Member
then if i understand it correctly, the distance from projector doesn't matter for the calculator, you take several measurements on various places in the building where people could be staring to the beam and the measured values will differ in power depending on the distance, is it correct? Thanks
Senior Member
Yes, but you should take worst case scenario, i.e. the nearest possible point of incident.
As the beam diverges with distance; the power density will reduce.
Doc's website
The Health and Safety Act 1971
Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.
Senior Member
yesterday i did a quick lasershow for school event in CZ
the guy who was one of the technical crew asked me about the specs of a laser and when i told him it's 300mW and it should be safe for the distance we used he told me: "oh well we use 1w for scanning at 5 meters" - there he left me a bit nervous if it's even possible to use it that way
even in kvant they told me up to 500mW should be safe at 7m, maybe they were using optics to produce some kind of fat beam but if not...
Posting Permissions
Reply With Quote
