O2 analyser cell testing?

Dear All,

I've a feeling that the O2 cell on my (home built) oxygen analyser is on
it's way out (Teledyne R17 MED).
Does anyone know what sort of output I should be seeing when tested with a
multimeter? - The specs say 7 - 13 mv in air, but I guess there must be a
figure for when it should be considered to be dead (and I should bin it and
stump-up for another :)

thanks
Matt

In article <ci4c49$d1e$1@mimas.salford.ac.uk>,
Matt <m.wetherill@salford.ac.uk> wrote:
>Dear All,
>
>I've a feeling that the O2 cell on my (home built) oxygen analyser is on
>it's way out (Teledyne R17 MED).
>Does anyone know what sort of output I should be seeing when tested with a
>multimeter? - The specs say 7 - 13 mv in air, but I guess there must be a
>figure for when it should be considered to be dead (and I should bin it and
>stump-up for another :)

Calibrate it in air, then 100% O2.

That'll soon tell you if it's a gonner..

Gordon

On Mon, 13 Sep 2004 15:22:08 +0000 (UTC), gordon@lion.drogon.net
(Gordon Henderson) wrote:

>In article <ci4c49$d1e$1@mimas.salford.ac.uk>,
>Matt <m.wetherill@salford.ac.uk> wrote:
>>Dear All,
>>
>>I've a feeling that the O2 cell on my (home built) oxygen analyser is on
>>it's way out (Teledyne R17 MED).
>>Does anyone know what sort of output I should be seeing when tested with a
>>multimeter? - The specs say 7 - 13 mv in air, but I guess there must be a
>>figure for when it should be considered to be dead (and I should bin it and
>>stump-up for another :)
>
>Calibrate it in air, then 100% O2.
>
>That'll soon tell you if it's a gonner..
>

Agreed.

If it won't give correct answers after air calibration followed by
testing with a selection of known gasses, it's toast.

At this point the mV are irrelevant.

Pete S.

Gordon Henderson wrote:
> Matt wrote:
>> I've a feeling that the O2 cell on my (home built) oxygen analyser is on
>> it's way out (Teledyne R17 MED).
>
> Calibrate it in air, then 100% O2.
> That'll soon tell you if it's a gonner..

Definitely. The failure mode for galvanic cells is that they
can't make enough max current anymore. The 100% then
21% test shows that up at once. Calibrate on 100% and
then read air. On a hot humid day in the tropics it might
be down a fraction (19.5%) but if air reads high the cell is
limiting and it is history.

nigelH

Thanks all!