R22 ???

Micko

Note from JR

Sorry I screwed up your post when I split the thread so I copied it..

Ok 3 new sensors this is mv in air

13.2 9.9 9.9 will go up to 10.2mv on sensors 2 and 3

100% O2

60.3 46.5 45.6

Any thougts guys sensors 2 and 3 seem off?

jradomski

nope sensor 1 is a bit off.. its just out of spec, and by the numbers you posted its not linear either, all your numebrs are a bit off but its the worse..

If you truely have 100% then then those numbers should be the air number multiplied by 4.78

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Micko

correction it is 98% O2 so sensor 1 looks bad then?
I will put Multi meda on all 3 see what i get.

jradomski

with 98% sensor 2 is almost dead on and sensor 3 is less tha .5 mv off

Sensor 1 is still the worse...

The r22 spec is 10mv +/- 3mv, I will take a sensor at 10mv over a 13mv sensor any day.. the higher the initial output the quicker (from my observations, and it makes sense since there is a fixed amount of chemical available and higer voltage means more electrons have to be released) they tend to die..

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Micko

??? the manual says between 8.omv and 13 mv is with in range of this cell.
Why is 13mv a problem i sill have trouble grasping this.

jradomski

the official r22 specs are rated at 10mv +/- 3mv so its slightly out of spec..

by your numbers the cell has a linearity problem, in 98% oxygen it should be 61.8 mv thats about a 2.5% error, so how bad is it at 1.3??

Cells with higher output tend to die quicker than cells with lower initial output..

the 9,9 cells should be reading 46.4 in 98%

so cell # 2 has a .2% error, cell 3 has a 1.7% error

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Micko

ok went for a dive my average PO2 was around 1.0 come home cleaned down kit now i think sensors are settling in. I think they are dancing around a lot.
There is no consistancy i will keep diving over weekend see how they come out.
Will they settle have people had these readings before?

Re Caled unit 12.7 9.7{ 8.5 to 9.0} now im ? sensor 3

98% 57 44.4 41.1

AD_ward9

Your sensors are contaminated. They will fail with less than the manufacturer's stated service life or shelf life. Would put bets on it.

I will now be contentious: Good sensors do not drift in 6 months. Unless they have dry joints or faulty components, they do not settle in either.

Before someone shoots me, I have a lot of data from a 5 year trial we have just completed (yes, taking 5 years as one of the sensor manufacturers claimed a 5 year service life - which turned out to be true). This compares with Teledyne who claim 36 month shelf life but nothing worked after 18 months for reasons we are starting to understand. We do not plan to make a lot of enemies by publishing all our data on sensors, but you can conclude that we have been underwhelmed by Teledyne sensors, both by some aspects of their design, performance and QA. Picture below is just one reason why: the open sensor is after 10 hours of use in an Inspo followed by 6 months of storage. Before anyone asks: no, it was not flooded.

One quick check to do is put the sensor in the palm of your hand, warm it, then take a reading using a volt meter. Then put it on ice, and take another reading. In air. Sorts out some of the problems.

Have a look at the April 2004 NEDU study, “Evaluation of Analytical Industries Inc. Model Number PSR-11-33-NM Oxygen Sensors for Use With the MK 16 MOD 1 Underwater Breathing Apparatus”, Document available on http://handle.dtic.mil/100.2/ADA443585, which approved the PSR-11-33-NM for Navy use to replace the Teledyne R10D. It is noted the standard deviation of the error of the PSR-11-33-NM is approximately half that of the R10D. We have more work to do, but right now we are quite impressed by the PSR-11-33 range.

Just to be clear, the 5 year sensors were from a Russian vendor, not from AI, but I do note AI have a 60 month shelf life now and are readily available. As I said, we have some more work to do, but the above statements are safe enough.

Alex

Attached Images

Resize of Used sensor compare.jpg (14.2 KB, 175 views)

Steve

Hi Alex,

Are the cells available commercially?

__________________
WARNING: I contain occasional coarse language, extreme sexual references, nudity, and adult themes, which may offend some people - Usually churchy types.

AD_ward9

Yes