Steam Machine Prizm?

[madmole]

Wazza, please do not play or take apart your unit until you are trained

You may do more harm than good, there are a lot of things on the Turtle that arn't on my site and that you will be trained in when you are certified. There are many O rings that need to be just so, and they are obvious to those trained so I dont include them

Take it easy and get on that course quick, but remember you need to do your advanced Nitrox class first. You are running before you can even crawl at present

 

[wazza]

Ok madmole I am not going to play with the machine,
And by the way I am an extended range instructor and advance tirmix diver , scr inst. As well. Don’t worry and thanks for your concern

 

[padiscubapro]

Shas once bubbled...
Wrong - the work of breathing is considerably less because of the increased cross-sectional area. This is considerably larger on the PRISM than the axial flow scrubber. The velocity is also slower and the PRISM canister is insulated from the water temperature so the duration and the pressure drop are considerably better than an axial flow like the Inspiration. This also affords the ability to condense out most of the water on the sides of the housing long before it gets to the sensors which makes for a drier environment for the sensors to perform.
[/B]

Looking at the numbers presented many of the test parameters meet the CE requirements I have seen(or at least appear to).. The tests do fail to disclose what the PO2 was set at for the WOB tests.. Since oxygen is a heaver element this will alter the WOB results. must be tested at a po2 of 1.6 bar@4degrees C

1 test that the prism can't pass (without different handsets)is the PO2 displayaccuracy, since you don't have digital po2 display..

the standard calls for display of +- 0.03 bar at po2 of .1-.4, and +- .06 bar at .4-2.0 bar

 

[Shas]

The secondary meter is +/- .03 bar accuracy or +/- 3% oxygen if you prefer - but this is the secondary back-up. The primary LED indicator light shift is absolute as it has a digital threshold and the accuracy is dictated by the sensor accuracy, which is +/- 1% FS to a maximum PO2 of 1.6. The gas control is as stated on the website.

The PO2's tested were 0.7 & 1.3 PO2 with a nitrogen/oxygen mix - the molecular weight difference is so small as to be negligible. However what is of far more relevance is length of hosing, pipework, internal diameter, pressure drop across scrubber, any sharp changes in direction or pressure drops across the mouthpiece etc, etc. These are far more significant in performance criteria.

 

[padiscubapro]

Shas once bubbled...
The secondary meter is +/- .03 bar accuracy or +/- 3% oxygen if you prefer - but this is the secondary back-up. The primary LED indicator light shift is absolute as it has a digital threshold and the accuracy is dictated by the sensor accuracy, which is +/- 1% FS to a maximum PO2 of 1.6. The gas control is as stated on the website.

The PO2's tested were 0.7 & 1.3 PO2 with a nitrogen/oxygen mix - the molecular weight difference is so small as to be negligible. However what is of far more relevance is length of hosing, pipework, internal diameter, pressure drop across scrubber, any sharp changes in direction or pressure drops across the mouthpiece etc, etc. These are far more significant in performance criteria.

I guess the secondary is up for interpretation.. The analog display will be showing the correct value (if calibrated correctly) but can the user interpret it that closely..

I didn't write the standards, but just quoted them.. the resistance measurements must be done at 1.6 bar..

Scrubber packing will also have a great effect on the WOB and will be variable..

The density using air as a diluent is only a few % between .7 and 1.6 but on a marginal design it could make a difference.. The prism appears to easily pass..
The big factor is if He is present or not and what percentage..

My comment wasn't meant to be nit picking, but someone started all this independedt testing in the thread.. testing is useless unless the test parameters are divulged.

For CE, the manufacturer doesn't have to publish the standards but the lab that did the testing must certify it met all test requirements.

The new CE standard for rebreathers is 39 pages long so far..

 

[caveseeker7]

The problem with the CE stuff for me is I don't know what exactly is tested, and within what limits a unit has to be to pass. That makes that little label abstract ... and completely worthless. And I don't think I'm gonna shell out $300 for 39 pages of info that should be FREE.
Aside from the fact that the certifcation of at least one unit seems questionable, which doesn't help in the value of the standard any more than manufacturers refusing to publish the results voluntarily.

Then I much rather do with a published report like the NAVY's on the Prism.

 

[madmole]

Gotta remember this is Europe. Here in The UK, ALL legislative papers covering laws are chargeable. Lawyers cant have the public actually knowing about this stuff :upset: Nothing is available for free for download. This includes motoring laws and stuff you need to know day to day

The goverment has a department HMSO, Her Magesties Stationary Office which publishes all standards and they have to make a profit. No "Freedom of Information act" over here. Care to come and remove the socialist government in the UK, when youve finished getting rid of Sadam

So the standards are available to all (as long as youve got money). But I agree they would be much more meaningful if we were all told what they were

 

[padiscubapro]

in the US the thinkg that protects us from inferior products is companies being afraid of being sued..
Also our "official" regulations in some instances are not easily reached..
case in point the new proposed OSHA regulations for rebreathers.. Ther is not 1 rebreather currently available that can meet the regulations, the closest right now would be the Infinito.. it could be modified to meet regulations..

The new proposed OSHA regualtions have 2 requirements that may be a surprise

1 - all rebreathers must have moisture sensors to determine if water is getting into the canister (this is pretty easy)
2) all rebreathers MUST have PCO2 monitoring accurate to .005 ata

 

[DrySuitDave]

Joe, how does the Infinito accomplish C02 monitoring....

Now if such a think can be added to the Turtle....

Ever get your unit yet?

 

[caveseeker7]

Thought about asking about the Infinito, but I've already been on Joe's case about the O2-integrated Explorer, the Meg, the Hammerhead ... poor sod.

CO2 monitoring isn't new, they use it on Hyperbaric chambers for example. But doing it cost efficiently would be. Expenses have been a limiting factor, then again the Infinito doesn't seem to spare them.

If I remember right Steammachines was messing around with CO2 monitoring, too, in the beginning. Dropped it because of expenses ... or was it problems with hummidity, can't remember.

Maybe Shas knows.

Stefan