[Gilles]

Just an idea.

Given the the sensor carriage could very easily be removed from the head via a suitable plug.... you then place the carriage into a ISC made/designed pot that you can plug all 3 sensors simultaneously.

The pot automatically logs and stores the acquired data from each of the sensors and one can view the data, interpret it, and judge the quality of the cells before trips/weekends/outings.

[Decodiver]

I cannot see the point?

You get air and O2 readings for the milivolts during calibration and a quick check at the start (and at the end if you so wish) of every dive will confirm you can push your cells past 1.6?

That for me is simplicity, and as I am stupid, I like to keep it simple.....

Cheers,

Dave Cooper.

[Gilles]

Quote: (Originally Posted by Decodiver)

I cannot see the point?

... I am stupid, I like to keep it simple.....

Cheers,

Dave Cooper.

Unfortunately, I am much the same

However, in my case I don't have easy access to fresh cells when needed. With the above, I can maybe predict (with sufficient lead time) when I need to change a cell, instead of needlessly keeping spares as they slowly deteriorate in my cupboard.

[Monkey]

Quote: (Originally Posted by Gilles)

Unfortunately, I am much the same

However, in my case I don't have easy access to fresh cells when needed. With the above, I can maybe predict (with sufficient lead time) when I need to change a cell, instead of needlessly keeping spares as they slowly deteriorate in my cupboard.

I am a new meg owner...so new I have not even been in the water with it... so take my question with that in mind

but I was planning on rotating cells our at predetermined time weather they needed it not.... say rotate the oldet cell out and a new one in every 90 days....

would this method not allow you to Predict you cell needs ??

[decoweenie]

Quote: (Originally Posted by dartagnansmith)

but I was planning on rotating cells our at predetermined time weather they needed it not.... say rotate the oldet cell out and a new one in every 90 days...

If you are saying that you will change 1 sensor each 90 days (~3 months), then it would an over-kill IMHO.

Personally, I found that a sensor will last fairly reliably ~12 months unless they fail early on during the first few hours/days/weeks. Most will last up to 18 months, but not all.

The best method for me is to buy some spare sensors about 3-6 months after changing, and keep them unopened. They do not deteriorate any worse than keeping extra unopened sorb around.

Having a cell tester is just a nice-to-have item but not completely necessary since you could check them u/w (PO2 and voltage), but you will also run the risk of cross-threading when keep taking them on/off... on top of wearing out the Molex connection as well.

[Monkey]

Quote: (Originally Posted by decoweenie)

If you are saying that you will change 1 sensor each 90 days (~3 months), then it would an over-kill IMHO.

Personally, I found that a sensor will last fairly reliably ~12 months unless they fail early on during the first few hours/days/weeks. Most will last up to 18 months, but not all.

The best method for me is to buy some spare sensors about 3-6 months after changing, and keep them unopened. They do not deteriorate any worse than keeping extra unopened sorb around.

Having a cell tester is just a nice-to-have item but not completely necessary since you could check them u/w (PO2 and voltage), but you will also run the risk of cross-threading when keep taking them on/off... on top of wearing out the Molex connection as well.

Ok say I rotate cells out at 120 days...... or 160 days..... my thought is to stagger the MTBF...

I used to be in the night club business and instead of waiting for a bulb to blow in one of the computer controlled dance lights ...we changed them out once they hit 800 hours..... this prevented them from failing when the club was opened and packed and it prevented them from failing catastrophicly.... so I felt the same logic should apply to cells.

[decoweenie]

Quote: (Originally Posted by dartagnansmith)

...my thought is to stagger the MTBF...

I understand what you are trying to do...

The difficult part is to balance the best balance between limiting catastrophic failures and cost.

Personally, if I were to use your approach, I would use the sensors at least 9 months (i.e. 270 days). That'd give the sensors a nominal of 3 months safety factor balanced against paying 25% more nominally.

Just my personal thought...

[Monkey]

Quote: (Originally Posted by decoweenie)

I understand what you are trying to do...

The difficult part is to balance the best balance between limiting catastrophic failures and cost.

Personally, if I were to use your approach, I would use the sensors at least 9 months (i.e. 270 days). That'd give the sensors a nominal of 3 months safety factor balanced against paying 25% more nominally.

Just my personal thought...

270 it is....thanks for your input and time.