NAPI Safe Diving Principles:

Part 2: Testing the Air Purity of your Compressor


Compressed air is the most essential ingredient in any dive outing. But not only is it necessary to have air, it also has to be pure. This means that the compressor used must pump clean air, but how does one test this?

Testing the old fashioned way

There are several highly or slightly less scientific ways of testing the air quality. The best way is to have a laboratory test the air. But this takes time, is expensive, and, well, annoying. The next best method is the do-it-yourself method, by using a gas detector bellows pump and tubes, such as provided by Draeger. This method is however not only a mouthful, it is also full of potential errors, and is thus unreliable. Not only that, it is not cheap either! Surely there must be an easier, cheaper, and more effective way of testing the air?

Testing the NAPI way

The NAPI method is simple: fill a tank, give it to your buddy, and go diving. The possible results are as follows:

  • Your buddy is missing. There is something wrong with your compressor, you'd better sell it now.

  • Your buddy has a splitting headache: too much carbon dioxide!

  • Your buddy has cherry-red lips: too much carbon monoxide!

  • Your buddy develops pneumonia: too much water vapour!

  • Your buddy develops lung cancer (in 20 years time): too much oil!


Simple, neat and effective. The above methods again show why it is so vital to dive with a buddy!

As before, if you believe this, please contact NAPI, we have a course just for YOU!


This page was last updated on : 06 Sep 2011