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May 1999 Vol. 14, No. 5   RSS Feed for Undercurrent Issues
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Regulator Testing Game

what's the best buy in regulators?

from the May, 1999 issue of Undercurrent   Subscribe Now

While we have long pointed to the U.S. Navy bench tests as the best information about regulator quality, these days the Navy seldom tests new regulators. However, Rodale’s Scuba Diving and the British magazine, Diver, have recently published their tests and opinions, and a review of these offers some useful insights.

Since Rodale didn’t publish its test procedures, the only real indicator of regulator quality is the assertion that each regulator has passed their standards for high performance. Each is a “tester’s choice,” and many are labeled “best buys.”

Diver, however, clearly explained its testing procedures, and the results were simply stated. Diver asked manufacturers to submit their top-performing regulator and one other for use in the water and bench testing on an ANSTI breathing machine calibrated to measure several variables, including work of breathing.

Four divers compared the twenty-one regulators at a depth of 130 feet. To simulate a worstcase scenario of a partner out of air, two divers tested a single first stage with two identical second stages. Partners would synchronize breathing to put maximum load on the system. Regulators were breathed wrong-way-up to test for water and also used facing into a current to check free flow. After the at-depth, in-water tests, the regulators were bench-tested on an ANSTI machine. No checkout or servicing of the regulators occurred after the intense week of test diving and before the bench tests.

The machine used a simulated depth of 160 feet at a temperature of 63 degrees F. with tank pressure at 750 psi. It breathed the regulators at 25 breaths per minute with a ventilation rate of 2.25 cubic feet of air per minute, a tough specification unlikely to be found in real life. Work of breathing was calculated. The bench test did send up some caution flags concerning a couple of regulators in extreme conditions. For example, both Beuchat regulators sucked in a lot of water at extreme conditions, and five of the regulators could not deliver the specified 63 liters of air per minute past the 150 foot depth.

The bench test did send
up some caution flags
concerning a couple of
regulators in extreme

Publications like to rely on the impressions of individual testers, but when it comes to regulators, these are highly subjective measures of personal preference only. Take, for example, some excerpts for the Aqualung Micra Adj. from three different testers: 1) “man, it’s brilliant”; 2) “I needed to make a real effort to inhale”; and 3) “switching to it was like slipping into overdrive.” Such comments show why we like to rely on bench testing rather than individual testers to evaluate a regulator’s performance.

From Diver’s analysis, we think four regulators deserve mention:

Apeks TX40 (sold in the U.S. by Zeagle). This is probably the best regulator tested by Diver, based both on machine tests and testers unanimously labeling it as “exceptional.” At $350, the Apeks TX40 is the best of the best buys. Zeagle also buys regulator parts from Apeks and makes its own version of the Apeks TX40, which it labels the Tech 50D. The Tech 50D has the same components and performance standards as the Apeks TX40, except that it has an external adjustment knob and a higher price tag: $483 for the U.S. version.

Mares MR22 Ruby. The MR22 Ruby delivered a very smooth performance and excellent machine-test results (only two regulators had better scores). However, at a list price of $799, it’s not a good value. Rodale’s lists it as a “tester’s choice” but does not give it a high-performance machine-test result. The companion Mares MR12 Voltrex has good tester comments, good machinetest results, and a much lower price of $481. Rodale’s lists the MR12 as one of its top eleven machine-test performers.

Scubapro Mk20/G250. This unit had one of the better machine- test performances. Testers found it outstanding (although a step down from the top), but, at $540, it’s hardly a best buy. Both Rodale’s and Diver agree that the Mk20/G250 had good machinetest performance.

Spiro Supra D XR2 Cryo - The D XR2 Cryo was very wellliked by all testers and is now available as the Cousteau D Cryo. At $480, it certainly seems like a good buy, but for some reason it’s not included in Rodale’s “best buy” list.

I have confidence in the presentation by Diver for several reasons: 1) the primary regulator tested for each manufacturer was that manufacturer’s own choice of its current best performer in tough conditions; 2) all their tested regulators meet the EN250 European standard; and 3) testers for Diver pushed the performance of the regulators to compare inwater performance at depth, and Diver then shared its tester’s comments.

My experience adds two factors: 1) how much maintenance the regulator needs; and 2) whether parts are available worldwide. From a maintenance standpoint, I greatly prefer the diaphragm design (especially with an environmental seal for use in cold or dirty water). I also prefer conventional design features so I can get the regulator repaired in some distant location if I need to. Aqualung/U.S. Divers, Beuchat, Mares, Oceanic, Poseidon, Scubapro, and Sherwood all seem to be widely distributed in the Caribbean, but the ease of getting offshore maintenance and parts varies widely, with Oceanic, Poseidon, and Beuchat having presented problems for me in this regard. On the other hand, problems with offshore maintenance and parts availability have been minimal with Aqualung/ U.S. Divers and Sherwood equipment.

— T. J.

Next issue: a look at the benchtest results.

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