Posts: 107
Location: milwaukee | Jono, my suggestion with the buckets and thermometer was to check the calibration at two points across the measuring range and to test against a known, reasonably good standard. Common practice in my profession.
I would not dunk my transducer in boiling water though. They are probably not rated for that temp and would possibly damage it.
So I did this test and here's what I got:
air temp per weather service = 84F
my thermometer = 84F
my air temp bucket water = 84F
Lowrance LMS-337 = 83.0F (error -1 deg)
ice bath @ 32F
my thermometer = 32F
Lowrance LMS-337 = 33.0 F (error +1 deg)
The interesting thing about the ice bath test was that it took about 1 hour for the transducer to get to 33.0F. After the first 15 minutes it was still around 50F. If they all respond that slowly, it might explain partly why there would be a difference between two units on the water that might have just come from different locations. That combined with simple error between units/mfgs and differing mounting depth below water on the transom would explain a lot.
Shep's point to just use it as a relative indication of water temp is a good one. |
