Airmar DST800 wrong water temperature?

[ColdEH]

Good day all . I have a new dst800 reading a water temperature 10 degrees on the plus side . I put it in the thruhull that the old nmea183 unit came out of and it was reading the water temp right. The unit is clean and only a year old . Any one else have this problem ?

Regards


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[GordMay]

10°C = 50°F
“Fast-response temperature sensor provides ±0.2°C (±0.1°F) accuracy”

[AnsleyS]

Check you display for temperature correction. Zero out any corrections and check against a dip thermometer.

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[DavefromNZ]

THREE TIMES!! I have had the temperature fail on the DST800. Twice replaced under warrantee last time refused. I am tired of the paddle wheel jamming with weed so about to fit the CS4500.


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[ColdEH]

Yep checked with a pool thermometer . 10 degrees difference . No calibration in my simrad is20 instruments or in my nss7 .

Not sure what else to do other then get a new one ?

Regards


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[BentP]

Didnt take long before the temp sensor failed in my DST800, I think it might be a piece of s...

[Paul L]

Originally Posted by BentP

Didnt take long before the temp sensor failed in my DST800, I think it might be a piece of s...

My dst800 temperature failed too. Sounds like a design problem.

[deblen]

Temp sensors in t-ducers are a chip that is fed 5 VDC.
Water leakage into a poorly potted chip exposes 5 VDC to salt water.
I'm retd from the business 15yrs now,but back in the day I replaced many bronze t-ducers with built in temp sensor due to this leakage & the resultant rapid electrolysis caused by it.

If the boat couldn't be hauled right away,I cut the +5 V wire at the t-ducer plug.
Moral of story-if temp readings go crazy-fix it fast!

Cheers/ Len

[tanglewood]

I've got a DT200 where the temp has gone nuts just as you describe.

[ColdEH]

I do have another thru hull , it has an old sensor in it at the moment . Maybe I will get just a temp sensor and put it in there . I have a nmea2000 network so I will just choose that input for temperature , better then changing the whole dst800 and then to find the same problem .

Regards


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[Kekaimalu]

Also had the temperature fail at about 30 months after install. It is reading about 18 to 20 degrees Celsius too high. It was part of a BandG package and sold by BandG. I have since learned that the temperature component fails first as it has a stainless-steel sleeve over the thermistor which corrodes especially if the transducer is left in the hull for extended periods. In our case the unit has been 'in water' off and on for significantly less than 12 months since install as we generally keep it inboard and have the blank plug fitted when the boat is not moving. So I am disappointed with this unit and would not buy one again. If I was to do the install again I would have a separate depth and speed transducer with the depth inside the fibreglass hull (as I used to have) which provides the unit greater protection. Since fiberglass has similar sonar characteristics as water, the sonar signal can pass through the boat hull with minimal loss. Also disappointed with Band G for not offering a replacement either under warranty or with significant discount. unfortunately they only warrant the product for 2 years. It seems that this is a known problem but there is no disclosures on the brochures about the temperature component durability, the need to keep it out of water when not in use, etc., so they really should not be selling a product that is not 'fit for purpose'. The total cost for the BandG electronics including radar, Zues3 9" chartplotter and three Trident2 Instrument displays was over AUD$11k plus the install costs, cabling, connectors etc., so a significant investment.

[Wetterbote]

Same here, with a DST200. It did read about two degrees to much even when it was new, but now it started reading up to 10 degrees to much. [I'd sure like to bathe in 26°C water now...]


Even a simple offset won't help any more, since the error seems to increase when the sensor is on. After startup, it is about 2 degrees off, but after running for several hours, it gets worse and worse, even though the water temperature doesn't really change at all.



I don't think it has to do with any leakage of the sensor, since the other sensors (depth and speed) work just fine. When there would be water in the electronics, these would fail, too.

[tanglewood]

Yes, they are utter garbage. That said, what's the alternative for depth and temp? The problem appears to be with the smart transducers, and the only alternative I have found is a fishfinder with a "dumb" transducer. The dumb ones seem to work forever.

[Wetterbote]

Originally Posted by tanglewood

Yes, they are utter garbage.

Have you seen other parts failing, too? I mean knowing the water temperature is nice, but not really important or security critical. Have you seen the depth measurement failing, too?


It appears there are no other vendors providing depth/log sensors for NMEA2000. You'll always get these Aimar transducers.

[redneckrob]

Originally Posted by DavefromNZ

THREE TIMES!! I have had the temperature fail on the DST800. Twice replaced under warrantee last time refused. I am tired of the paddle wheel jamming with weed so about to fit the CS4500.


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Holy cow, those things are $800! I got all excited about replacing mine as well until I checked the price.