Regulator Tests

Many manufacturers have started showing charts and graphs displaying their regulator performance. But we have noticed that some- including some major manufacturers- don't show the rate of breathing! It's a bit like claiming your car gets 70 miles per gallon, but failing to mention that you measured it when heading down a steep grade with a tailwind. We suspect that many of these tests were done at very low rates of breathing, 25 liters per minute or less, to create good looking graphs. For comparison's sake the top test to the right is a Zeagle Envoy at a MODERATE rate of breathing- about 37 liters per minute. Compare this to the next Envoy test chart below it, done at a heavy rate of breathing of 62.5 liters per minute. The "Work of Breathing" result is significantly lower with all of the same criteria except a lower breathing demand of 37 lpm.  Often the lower breathing demand is not noticed when looking at the chart.

The two graphs on these charts show 1) the inhalation and exhalation effort(top graph) forming a loop (the bigger the area within the loop, the more effort expended to breathe), and 2) the intermediate pressure (bottom graph)through the breathing cycle. In both cases a flat line in the middle would be perfection. All of these tests were conducted with the breathing resistance knob in the middle- not the optimum "full out" position.

Important things to note in evaluating test data are the

• Depth
• Breathing rate
• Overall work of breathing
• The SMOOTHNESS of the curve (large spikes indicate instability and "juddering"- this is one area where Zeagle regulators are truly exceptional)
• Was the test objective and independent, conducted according to recognized standards?

The links here display the breathing performance test data for Zeagle regulators.

These tests shown were conducted at Dive Lab in Panama City, FL under the same conditions used to evaluate regulators for US Navy use.
• a breathing rate of 62.5 liters per minute
• a tidal volume (lung volume) of 2.5 liters
• Depths of 198 feet of sea water (some tests here are deeper)
Actual testing like this, with the regulator under extreme conditions of depth and heavy breathing, is the only way to objectively evaluate a regulator's performance.You can't get this kind of information from casual diving, and certainly not from breathing from a regulator in the shop!

The US Navy standard for a "group A" regulator is that under these conditions the overall work of breathing does not exceed 1.4 joules/ liter. During US Navy Class "A" test conditions, all of the Zeagle regulators were below 1.0 joule/ liter, which is a level of performance very few regulators can claim. The Flathead VI demonstrated a work of breathing still well below the Navy standard at a depth of 307 feet, the limit of the test chamber!  To increase the strain on the regulators even beyond the US Navy Tests, the inlet pressure was lowered to 750 psi.  The graphs attached to this page show the incredible performance even with a tank that is near empty!  Naturally, no diver would ever be at these great depths and breathing rates with less than 750 psi in the tank, but it is nice to know that Zeagle regulators can offer such low breathing efforts even under these extreme conditions.

Of course, raw performance is only part of the story. Reliability, simplicity, and ease of maintenance are also built into every Zeagle regulator!