Re: MR-12 and MR-12 II?
Posted: Mon Mar 03, 2014 12:09 pm
I have searched through my collection of NEDU documents to see if I could find any data that would apply to your question as to whether the larger exhaust tee of the MR12III provided lower exhalation resistance.
The NEDU tested the MR12III in 1987 and found that the exhalation effort measured 11cm of H2O at the MilSpec setting of 40.0RMV at 198'. The same NEDU procedures were used in 1980 with the MR12, MR12II, and R14 Polaris models. While there was a very slight difference between the three different examples, they all scored in the same 11cmH2O range. From that data, it appears as though the larger exhaust tee did not make a discernible difference in exhalation effort.
As far as the Trident "A145-69mm, Round black diaphragm" goes, I have no experience with it. I would be very much interested if it is compatible. The Mares Abyss diaprhragms are very high quality, but expensive.
Greg
The NEDU tested the MR12III in 1987 and found that the exhalation effort measured 11cm of H2O at the MilSpec setting of 40.0RMV at 198'. The same NEDU procedures were used in 1980 with the MR12, MR12II, and R14 Polaris models. While there was a very slight difference between the three different examples, they all scored in the same 11cmH2O range. From that data, it appears as though the larger exhaust tee did not make a discernible difference in exhalation effort.
As far as the Trident "A145-69mm, Round black diaphragm" goes, I have no experience with it. I would be very much interested if it is compatible. The Mares Abyss diaprhragms are very high quality, but expensive.
Greg