beginner in need of explanation

I had not any experience with this stuff but I visited their site. Unfortunately I couldn't find any manual for downloading.

1. Will the decible (dB?) reading be the same from 2 feet away as it is from 50 feet away?

You can check it out by using any constant origin of noise. I'm supposing that as default it can measure noise level just at place where it located, but I suppose also (studying how it looks like on photo) that it can be programmed to measure noise level remotely on distance what you need.

2. What are the safe ranges I am looking for?

It depends on national/local rules so you have to find it out yourself how to meet any legal deeds. As I know 80-85 dB is commonly limit of noise level for industrial environment.

3. is it important how long the "bang" lasts for?

Really I do not know is it important? Any bang hopefully has to fade along its produced noise. Do not be confused this meter should be applied for measuring THE NOISE --- not and the impact wave!

As I could understand from meter's spec it can be connected to PC through RS232 so you can log all your data to hard disk being safely apart of testing site.

If your measurement may cause any tiny risk. I recommend you urgently to ask any experienced person for assisting you in developing and experiment fulfilling.

In my land anyone should make a lot of paper works (writing methodics, programs etc ), approve these tons of docs and then only be allowed to conduct any field experiments.

Hope it helps.

Take a look here. It seems there are answers on most of your questions. Exposure time is connected with yours product "bang" duration.

Will the deciBel reading be the same from 2 feet away as it is from 50 feet away?

No it will not. The standard industry distance is 1 meter ( or 3 ft if you are in the US)

What are the safe ranges I am looking for?

Less than 85 dB at 1 meter is considered normal exposure (in my industry, yours may be different). Anything more than this requires personal protective equipment.

is it important how long the "bang" lasts for?

Impulsive sound can be more damaging to hearing and the dB limit should be reduced.

and does anyone know the 1354 model and how to use it?

There are two ways of using this meter. The first is in SPL mode, which will give you a real time sound pressure level ( again measure at 1 meter from the noise source).

The other mode is dose mode. In this mode the meter is attached to a worker who wears it for a normal shift. At the end of the shift you can read his noise exposure.

Thank you, of all the answers, yours really helped me.

Look here:

http://www.cdc.gov/niosh/topics/noise/

And more information is available regarding standards on the ANSI website:

http://www.ansi.org/

You may wish to get ANSI S1.25-1991 on Acoustics as a starter. Unfortunately, you must buy these documents and they are rather pricey. Good luck with your project. Acoustics is a peculiar beast.

Will the deciBel reading be the same from 2 feet away as it is from 50 feet away?

If you're doing your test in free air (outside), the dB reading will not be the same. Sound level drops the farther away it is from the source.

If it's inside a room other than an anechoic chamber, you need to deal with reverberation. The sound level will be nearly constant at different distances but will take longer to die out. I imagine, however, that you're referring to the outside.

What are the safe ranges I am looking for?

Others have already answered this.

is it important how long the "bang" lasts for?

In what way are saying "important"? Important for the effect? Or on how much it affects humans? The longer it is, the effect (for entertainment value) is better but bad for humans.

and does anyone know the 1354 model and how to use it?

No, I don't unfortunately. I tried checking the 'net but no luck on a manual.

Thanks Everyone! Got my answers! What a great Forum