rEvo rMS 2018-06-18T19:30:53+00:00

rMS, What does it do?

The rMS is really unbelievable, it is not a temp stick or anything like a temp stick. It is real time calculation on the performance of the scrubbers. It gives you a prediction on the longevity of both scrubbers. The display states how many minutes that remain before you need to cycle the scrubbers (repack the top scrubber and place it in the bottom scrubber housing and move the bottom scrubber to the top housing) and how many minutes remain before you need to repack them both.

The calculation is based on data and several other factors.

Your breathing rate. The harder you breathe the more carbon dioxide you produce. The more carbon dioxide that you produce the faster the scrubber is expired. This information is collected as the position within the scrubber that the reaction is taking place is moving faster.

Your depth. The deeper that you are the more dense the gas is, the greater density of the gas means that the absorbent material is used a higher rate.

The water temperature. Water temperature has an effect on scrubber duration. In simple terms the colder the water the quicker the absorbent is exhausted.

It is personalised as well. One person can produce a higher amount of carbon dioxide than another and as a general rule men produce more than women. Also larger people produce more than slight people. The rMS takes this into consideration. You programme into the unit your gender and your weight and it uses those parameters for the prediction.

What this all means to me is that I know how long I have remaining on my scrubbers at any time during the dive and that information is displayed in hours and minutes. There’s no longer any guesswork.

A real life example was in summer I was diving a “U” boat at a depth of 70 metres with over an hour of deco and the shot line was well off the wreck. The current had changed and I was fining hard against the current to get to it. I looked at my display and instead of seeing the information in green it was a clear “10” in red. This meant that I only had 10 minutes remaining on the top scrubber if I maintained the same work rate at that depth. I still had the bottom scrubber so I wasn’t worried but I slowed down the work rate and as I got to the line and waited a minute for my buddy the expected scrubber life on the display was extended.

At the first stop I noticed that the remaining scrubber prediction for the top scrubber was now again displayed in green and around 45 minutes were remaining. When I was on the deco trapeze at 9 metres the water was much warmer and the breathing rate calm the remaining scrubber time on the top scrubber was well in excess of an hour. This highlighted the fact to me that the rMS wasn’t a way of extending scrubber life it was a tool that could give an accurate prediction on the longevity of the scrubber.

This is the rEvo rMS. If you have any questions about rMS or any aspect of the rEvo Rebreather then please do not hesitate to contact us

About the author

Simon is a highly experienced technical diver and rebreather instructor, teaching everything from entry level rebreather diving to 100m mixed gas CCR diving. He has been both diver and owner of many rebreather units including: AP Inspiration, AP Evolution, KISS, Sentinel, Megladon and he his now responsible for all UK rEvo Supply and Training having found what he considers to be the perfect rebreather in the rEvo. You can follow Simon on Facebook at or on Twitter