i300 Inaccurate Temperature readings

[JAB110]

Hello - I am a newly certified diver, and the shop where i certified recommended the i300 dive computer, which i bought from them. The first time i used it was on my 4 cert dives over the weekend of May 6/7 at Lake Denton in Avon Park, FL. Well, my computer registered temps of 87 and 88 for those days, where as, everyone else's registered 82. Then, the following Friday (5/12), i did 2 dives in the gulf and my computer again logged a temp of 87. I spoke to the shop owners where i bought the computer and they said fluctuation was normal and it's not typically all that precise. They also suggested that it may "self calibrate" over time. I find this very disappointing, not just because it seems poor for such new technology, but since i was advised during training to keep my log up to date with wetsuit thicknesses and water temps so that, over time, i get a feel for how much wetsuit i need to stay warm.

Has anyone else found this issue with the i300? Or am i just misunderstanding the use of this information and i really should be getting the water temps from an outside source? I checked the manual and it said that this should be the lowest temp reached, but it's pretty unlikely that the gulf was 87 degrees at 30 feet on May 12 (near Venice Beach). Thanks

 

[NCadiver]

Have you compared it to a real thermometer? How long are your dives? What the temperature of the computer before you get in the water?

 

[JAB110]

Hello, thanks for the response. I have to say that the temp reading on my computer for the cert dives actually seemed to match the air temp those days, but i really didn't check it before entering the water so can't swear to that. It was more based on the weather predictions those days (was quite nice out and expected to be mid to upper 80s).

When you ask how the water compared to a "real" thermometer, i really don't know. I remember checking gulf temps in the area before going to Venice and it was just under 80. (Even today, the high was reported as 83, and i think that's surface.) All i really had to compare to was the dive computers used by the other divers, and they all showed lower readings (as listed above).

As for time in the water, the cert dives were anywhere from 1/2 hour to 75 minutes each, but as you would guess for such a thing, it was not all spent at the bottom. The 2 dives i did in the gulf were each 60 minutes, with the entire time spent at the bottom (appx 30 ft).

 

[JAB110]

I have to add, your note made me think - why not just check the thermometer readings in a "known" room? My living room. (Probably should have thought of this before, but i guess i thought the computer didn't start really "doing work" until it got to a certain depth... Not so.) Anyway, i turned it on and waited. The thermostat was set to 78 in the room but current temp showed 77, so pretty steady (no AC coming on etc). My dive computer reading after about an hour in this room - 89! It slowly crept up toward this point, but i even watched it tick back down to 88 and found that room had cooled by 1 degree too. (It was in the evening.)

Now if you can think of a reason this air temp reading should not be accurate, please let me know. Otherwise, i think this device had a faulty sensor (or it's calibration is off anyway).

 

[NCadiver]

The temperature is off on your computer. You will need to send it back to get it calibrate.
The short the dive the less accurate the temperature is on the computer.