I just found this on another board, hope it helps, as I am new to all this and researching my options for gear also.
Atomic Aquatics M1 Regulator
by CapeCodDiver
Date: 2002-06-13
Category: Regulator
I recently purchased a new Atomic Aquatics M1 regulator to replace my veteran Atomic B1/T2. The M1 is Atomic’s entry into the tech market. They have made the new regulator extremely tolerant of Nitrox blends.
The M1 is Atomic’s entry into the tech market. They have made the new regulator extremely tolerant of Nitrox blends. The M1 can be used with up to 80% O2 concentration at a maximum pressure of 3000 psi when dedicated to Nitrox service only*. A non-dedicated regulator is rated to 50% Nitrox.
Let’s start with the marketing hype from the Atomic web site and then break it down.
“The M1 has an expanded performance range to meet almost any diving condition imaginable, whether recreational or Tech. The M1 features a relatively new metal to the diving industry – Monel. Monel parts are used internally in the first stage for it’s high strength, corrosion resistance and oxygen compatibility. In the second stage, the new anti-surge front cover is designed for use in high current situations to eliminate the possibility of free flow due to water action on the diaphragm. The exhaust deflector has been extended to enhance visibility by better deflection of the exhaust bubbles. For cold water diving, the first stage has been factory sealed and the second stage features a thermal heat sink and improved super-dry exhaust valve.”
How did Atomic achieve this high Nitrox standard? Virtually no titanium in the first and second stage valving is exposed to the breathing gas eliminating the possibility of titanium burning when exposed to high concentrations of oxygen under high pressure. The first stage is made out of Monel, a nickel-copper alloy, and brass. The second stage uses a plated brass valve housing similar to the housing found in their entry level Z1. The second stage orifice is stainless steel with a stainless steel heat sink to reduce the chance of freeze ups in cold water. Without resorting to Atomic’s tech drawings, it appears that the only titanium parts in whole regulator system are the second stage lever spring and the poppet return spring. This is an interesting new direction for the company that introduced titanium regulator technology.
Visually the M1 first stage is identical to the B1 first stage. However the visual differences on the M1 second stage are obvious. The stainless steel heat sink shines brightly where the low-pressure hose enters the second stage housing. The exhaust tee has been extended by about 1/2 inch on each side to "reduce bubble interference". The purge cover now has side ports instead of the front ports on other Atomic second stages, purportedly to prevent a free flow in strong currents. While neither of these “problems” was an issue with my old B1, after 30 dives with the M1, I liked the new exhaust pattern enough to retrofit my old B1 with the new exhaust tee.
The new M1 breathes as easily as my old B1 but that was to be expected as the internals of all Atomic first stages are virtually identical. I have not yet seen the technical drawings of the M1, but apart from the new first stage valve and piston seat modifications, I expect to see no internal changes. Externally, a new rubber cap on the first stage identifies regulators with the new Jet Piston. The first stage piston and seat have been redesigned to solve a low-pressure creep problem that occurred with high-pressure tanks. I did have this problem with my B1. It was a pain but not a big issue. Because of a very slow intermediate pressure creep, the regulator would have a tiny free flow when left to sit on a 3500 psi tank. It would stop when I breathed the reg or the psi got under 3000. Even after two rebuilds, the problem remained. The upgrade to the new “Jet Piston” is available for your current first stage from your Atomic dealer. I purchased the kit and have installed it on my B1. A quick test this past weekend showed no creep in an 18-hour period, so I think the problem has indeed been resolved. The kit retails for about $60.00 and can be installed during your normal service without incurring additional labor costs.
The M1 first stage has an environmental seal on it. Nice feature but it may make servicing the regulator a pain. They create the seal by filling the ambient chamber of the first stage with Christolube and sealing it. All that grease will have to be cleaned out and replaced when the regulator is serviced and Atomic recommends using a special tool for the job. Another $30 goody your local shop mechanic has to acquire. I should note that I had to clean up some excess Christolube that was expelled during my first dives with the new equipment.
I am quite happy with my new M1, but is it appropriate for everyone? Not really. Remember, all of the Atomic regulators have very similar performance characteristics. They are all solid reliable equipment designed by former ScubaPro engineers. The average recreational diver will be well served with a Z1. Do you dive a lot? Splurge for the B1 and you can get a first stage swivel, titanium valve body in the second stage and you extend your service intervals to two years. As for the T1, very few folks have the budget to buy a titanium-bodied regulator that is twice as expensive as the company’s next best offering with virtually no performance improvement. Using the link below, you may see pictures of the entire Atomic Line. My local dive shop has priced the Atomic regulator line as follows. T1 - $1598, M1 - $698, B1 - $630 and Z1 $379. Make your own call.
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*Nitrox warning From the Atomic owner’s manual:
NITROX (EAN) USE – M1 ONLY
Important notice – read before you use this regulator
The M1 has been specially designed to handle high EAN mixes. The M1 may be used interchangeably with air or EAN mixes up to 50% oxygen concentration at 3500 psi maximum. It need not be dedicated for EAN use, provided that it is used with air or EAN mixtures that meet minimum dive industry purity standards. If the regulator becomes grossly contaminated with dirt, oils, or greases from any source, have the regulator re-cleaned before using it again with EAN. The M1 may be used with up to 80% oxygen concentrations at a maximum pressure of 3000 psi, provided it is dedicated for this service and kept in an O2 clean condition. This is a special-use condition, intended only for those persons trained and certified in safe handling of high pressure oxygen/oxygen mixtures. O2 cleaning requires a more stringent level of cleanliness and special care should be taken to keep the regulator in this condition.
Do not use silicone or hydrocarbon greases in or around regulators being used for EAN Nitrox or oxygen mixes.
