Pressure reading unstable

[Nick Fleming]

Apologies if this has been discussed already but I couldn't find anything using the search function.

MY OSTC 2n (2974) is giving me a fluctuating mbar reading when I switch it on. I asked my buddy about this who has a MkII (No 992) who initially said his reading was stable but then one evening his also fluctuated. So I assumed it was just down to possible ambient conditions and I ignored it. That was until today when we had the units side by side. My unit was fluctuating (every 2-3secs) between 1001mbar and 1010mbar while his was static at 1000mbar.

Is this something I should be concerned about and does anyone else's OSTC do this?

Many thanks
Nick

[Solodiver]

Same FW? Beside that, this is common and nothing you should worry about...

Jan

[Chilihead]

FW 2.0:
Ignore 5mbar pressure sensor noise in surface screen

+-5mbar = 10mbar

[Nick Fleming]

Yes, Firmware 2.0. I just got the 2N last week though and it did the same when then Firmware was 1.9. Sometimes it doesnt fluctuate, and most of the time it only moves +/- 5mbar, but today it was closer to 10mbar so thought I should ask.

Thanks for the replies. Much appreciated.

Nick

[Nick Fleming]

Apologies... my +/- is incorrect. +/-5mbar covers the fluctuations seen today. It moved at total of 10mbar. Usually it only moves 4-5mbar.

Just wanted to be sure so I dont doubt it when I'm in 2m viz on a deep wreck with bad narcosis!

Again...many thanks
Nick

[heinrichsweikamp]

Hi,

5mbar (=5cm water depth) noise is normal - we should add some more averaging to this value in the future. The value is displayed in surface mode if it's +/-5mbar compared to the reference value. This may result in a max. of 10mbar variation.

Cheers,
Matthias

[Nick Fleming]

Matthias and Chilihead,

Again, thanks for the advice. I knew the +/- 5mbar was not huge in terms of water depth but was just checking that it wasn't a sign of a more serious problem with the sensor. New comuter you see and I've had a lot of faith up until now in my Suunto Vytec so just wanted to be 100% with the OSTC.

Must say though that the OSTC looks amazing underwater (buddy has been showing off his to everyone since he got it) and with this kind of support I'm delighted with my new purchase.

Looks like the Vytec, my trusty companion for many dives, is about to be relegated to gauge mode!

Appreciate your help.

All the best
Nick