Posted by tecdiver on August 14, 2002 at 13:20:15:
In Reply to: Re: Hydro on the Spot posted by Peter on August 14, 2002 at 12:30:37:
This is actually a good question. To date this is the best answer I have. Some stores will have the state issue them a certificate stating the quality of the air, by stating the individual contents in ppm. OWH does have extremely low contamination, they also use a oil free air compressor. No the shop and no your air. The other way if you are not sure and want to spend the effort, would be to take a cylinder you are sure of with a little tested air. You can by sampling kits. Take the cylynder to the store get a fill. Go home take a sample. Send the sample in and see how it comes back. Now remember the best time to sample air is at the end of the filter media time, this would be hard to know if you are not familiar with the shop. This way is time consuming and do not tell the shop ever you did this, they do not seem to appreciate it. Another way maybe not as scientific but I have done it before. Take a clean cylinder you are sure about. Use that shops air in question in that cylinder for several air fills. Over a period of time not long may I had in some cases, check the cylinder each time before the fill. If you see moisture or any type of residue, in the bottom or flashing, stay away from that air. Boats are a problem, the best thing, but this may be costly, dedicate tanks for your boat diving. You could by a personal filter, you do have to change the media often if you do a lot of fills. On some boats, no names, one fill could do your filter media in. If anyone has better ways I would like to hear.