PDA

View Full Version : Cells.



Dacmirc
29-01-2016, 05:20 PM
Hi just a quick question before i give the shop a call.

Basically ive always bought cells from my local dive shop and they have been dated that month or the month before however ive just got home from working away to find the cells i ordered and recieved 2 weeks ago are dated 2015-10. Would this be the norm or should i give the shop a call.

Sent from my SM-G900F using Tapatalk

matt
29-01-2016, 06:14 PM
I don't think 3 months old is too bad, I've had worse.

ARJAYM
29-01-2016, 07:08 PM
Pretty average I would say. Bit of luck of the draw really last of an older batch or first of the new.

Not a massive bearing on how long you will get to use them.

Dacmirc
30-01-2016, 07:40 AM
No worries. Cheers lads

Sent from my SM-G900F using Tapatalk

clique
30-01-2016, 01:45 PM
Just to add to this, I've possibly got some cells from the same batch (APD16s) which I got last weekend. How much variation would you expect between the raw mV values when calibrating? I'm seeing cell 1 and 2 around the 0.92 mark and cell 3 was reading 1.03.

Just a little surprised to see that much deviation from 3 brand new cells.

matt
30-01-2016, 03:03 PM
Just to add to this, I've possibly got some cells from the same batch (APD16s) which I got last weekend. How much variation would you expect between the raw mV values when calibrating? I'm seeing cell 1 and 2 around the 0.92 mark and cell 3 was reading 1.03.

Just a little surprised to see that much deviation from 3 brand new cells.

They are fine. They are nominally 10mv.

From your training and diligent reading of the manual you'll know that the unit will calibrate with cells between 7.6mv and 13mv. ;-)

You'll also recall that the end-cal-values are equivalent to the standardised 10mv cell in air with the decimal shifted (/10).

So you're getting 9.2mv and 10.3mv. You can check by pressing the left-button 4 seconds unless you have a Classic, or very old software.

The lower the mv reading the more likely they are said to last - my experience is that those under 9-10.5mv all last the same. Those higher than 11mv tend to be duff.

The actual mv output is not so important. Checking for current limiting (which you can test in water, O2 flush to 1.6 @6-8m), linearity (in a pot) and consistency (check those end-cal-values each time you calibrate, they must be stable, and check in air, they should read 21% with the lid off).

Sorry if this is sucking-eggs.

Cheers,
Matt.

MadUKDiver
01-03-2016, 07:03 PM
Better late than never... the Teledyne specification for output was "7 - 13mV in Air at 25C sea level"

So 9 - 10 mV is perfectly fine.

MadUKDiver
01-03-2016, 07:21 PM
Having laid my unit aside since November due to work pressures (and weather) I just started getting it ready for some action last weekend. I thought I would give the old cells a quick check before replacing them.

There are 4 in my lid ...
2x Narked at 90 NANS01 (http://www.narkedat90.com/coax_sensor_p/nans01.htm) (equivalent to AP16) - Manufactured Apr-2014, Age 22 months
2x APD APD14 (http://www.apdiving.com/shop/oxygen-sensor-coaxial-apd14.html) - Manufactured Jul-2014, Age 19 months

For the two N@90 cells, one was current limited at around PPO2 1.1 bar and both show signs of caustic electrolyte leakage (with corresponding green nastiness on the gold SMB connectors and the solder on the circuit board in the sensor blackened).

The AP 14's were still going well though.

I have to say I was a bit surprised about the NAN's leaking as they performed so well all last season and everyone was raving about how great they are. I think CL and leaking at 22 months since manufacture is a bit premature even though 18 months is the limit for use underwater. They are both the same batch so maybe just a 'glitch'.

I have more AP14's on order now.

matt
04-03-2016, 08:27 PM
I have also had problems with the leaky N@90.

Paulo
04-03-2016, 08:28 PM
The APD14 must be very popular as they are on back order

Vanny
04-03-2016, 08:43 PM
So are the 16's , 3 week wait.

At least they should be recent dates !