Shearwater on the PRISM

Chris

HI Andy
I am not getting it? The voltage running to the secondary cable is direct from the sensors yes? So if the SP Controller or solenoid fails that’s not going to worry the secondary data, so you just fly manual off the Shearwater Handset?

The Shearwater would interpret the data coming off the cells the same way the Kiss does, as raw voltage. Just got to figure out how to calibrate it, as the Shearwater has calibration inbuilt so negating the need for the PRISM's Cal Pots, I am thinking you would have to bypass the Cal Pots and hardwire that connection and in so doing Calibrate the secondary (Shearwater) from it, and ditch the Cal Pots altogether. Anyway I am just throwing it out there, I would soo love a wiring diagram for the PRISM head would make all this much easier.

Cheers
Chriso

__________________
Megalodon
Sorb and Sensors whilst in Australia www.divetub.com.au
Diving & Photography @ www.uwphotog.com

silent running

Chriso, not trying to confuse, just thinking in print. I was wondering how the SHW would interpret the raw Mv low current into digits. The KISS has an amp and other hardware that the raw Mv's go through before appearing as digits. My understanding is that even those raw Mv values have to be amplified, then interpreted by the hardware and averaged into a stable, digital reading of the sensor outputs. I was wondering if the way in wich the SHW does this to produce steady readings, is any different from the way in which the Prism SP controller interprets the Mv data and manages your O2 injection? And if so, could it be different enough to cause someone to think they are at one SP and the electronics think it's another? Probably not much of a difference... I like your idea and will be interested in the out come. -Andy

dive2dive2000

Chris,

I had a long talk with Peter about the pros and cons of the secondary. for the type of diving I do, cold and dark, I was concerned about the sensitivity of PRISM'S secondary. The big misconception that I was under was as long as there is a seperate battery supply it was worth the risk of having a digital read out on your secondary after all the out put is still direct from the sensors. As peter explained and as I understood the danger comes were if there is a small amount of water ingress your digital display will still function, but give a false read out. So if your electronics freeze, or crap out you are know depending on a digital display with know way to confirm (except dill flush and...). With the PRISM's true anolog display you have a visual meter that will inform you of water or electricall ingress, and now that can be backed up with a dill flush and... It is an invaluble option and although it is a fragile instrument I believe it is worth it. I was a little shy in asking him at first (dont want to insult owner of co.) but glad that i did. I would call and get info right from him before making a deceiding. Hope this helps

__________________
Safe Diving,
Martin

dive2dive2000

How does that saying go God had an "Inspiration" He went out and bought a PRISM

__________________
Safe Diving,
Martin

decoweenie

Just curious...

How long did God have to wait for it to be delivered?

And did the code got shifted out of place from the transport ?

B2CCR

The fewer batteries, wires, circuits and digital displays in the mix the better. I'm not sure why people believe digital displays are more accurate than analog. Think about the entire process. Did you have pressure gauges calibrated against a NIST standard this year? How about the volt meter you are using to test your sensors? And the temperature gauge that you used while filling your tanks?

This whole process, and by that I include open circuit mix diving, comes down to; measure with a micrometer, mark with chalk, cut with an ax.

Oh, and did I mention the fact that we are all using decompression "MODELS".

Bruce
NJ, USA

caveseeker7

Less time than the first batch of Evos took ... or the second, third, fourth ...
Then again, time is relative on some units.

Not the only units with code problems, and SMI certainly didn't take 9 month to fix it.

Besides, He couldn't really get something named Evolution

Probably because of the two or three digits behind the decimal point.
It looks really, really accurate.

Now that's an instant classic, Bruce.

__________________
Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

mverick

Didn't someone retro fit a Hammerhead onto a Prism?

Might be another idea.

I like my Shearwater though. But the new one is different.

I wouldn't even consider waiting for ANY Prism upgrades. Like the Video Hud. It was supposed to be out around 5 years ago. At OurWorld Underwater in Chicago they told me 4-5months. 5 years ago. Man, that's a long development period.

I wouldn't even wait on the Apecs 3 for the Meg. I've been waiting about a year to hear the new scrubber is out.

Shearwater is out in Beta at least. And it seems to have updates on what's going on with it. Nice in this world. To be informed. Other manufacturers could learn a lil. And telling me it'll be out in a lil while. Isn't info.

Kinda funny how a Uwatec bottom timer works like it's supposed to underwater. And the Cheap air dive computers work well underwater. Get to a $1500 dive computer or a $8000 Rebreather and they have problems.

B2CCR

Mine goes to 11......


Bruce
NJ, USA

wizbang

Chriso, will the shearwater give you SP and Battery readouts.?
If I read correctly that you said no and you can live with that.

but ...

then you would need to carry both the analog and digital version for every time you want to check the battery or change/check set point. (not often I admit but...)

Don't get me wrong, I like the idea of digital instead of analog.

For those that LOVE the idea of the analog and its redundencies there is no alternative, but for those that dislike the fragility or not seeing all three sensors at once, is not such a big problem, considering it is the then the same risks as most other rebreathers with digital read outs.