Sans Bateau
Well-Known Member
The water temperature reading on my ST50 system is wrong, for instance in the summer it will be reading about 8deg, at the moment it is showing -10deg! Anyone experienced this, any remedy?
ST 50 temp reading
- Thread starter Sans Bateau
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Phoenix of Hamble
Well-Known Member
I seem to remember that there is an offset adjustment, but my manuals are at home.... will look later!
SkipperMarv
Well-Known Member
I had a quick look here and couldn't see a calibration for the temp?
misterg
Well-Known Member
[ QUOTE ]
The water temperature reading on my ST50 system is wrong, for instance in the summer it will be reading about 8deg, at the moment it is showing -10deg! Anyone experienced this, any remedy?
[/ QUOTE ]
I don't think there's any calibration.
I believe it uses a thermistor (resistor that changes its value with temperature) as a sensor, so poor connections (high resistance) could cause it to read low. Unless you've cut the cable somewhere, the only connections are on the back of the instrument - worth a check? (A bit of moisture there could cause all sorts of problems, too.)
Andy
The water temperature reading on my ST50 system is wrong, for instance in the summer it will be reading about 8deg, at the moment it is showing -10deg! Anyone experienced this, any remedy?
[/ QUOTE ]
I don't think there's any calibration.
I believe it uses a thermistor (resistor that changes its value with temperature) as a sensor, so poor connections (high resistance) could cause it to read low. Unless you've cut the cable somewhere, the only connections are on the back of the instrument - worth a check? (A bit of moisture there could cause all sorts of problems, too.)
Andy
iangrant
Well-Known Member
Stephen:
There is no calibration adjustment for the Temperature in the ST50 Speed. To see if there is a fault with the transducer assembly, do following test;
Disconnect the transducer cable from the display head and locate pins 1 and 2. You do this by facing the plug end of the instrument cable with the reference notch at six o'clock position, Pin 1 is at 7 o'clock and pin 2 is at 10 o'clock position. With the instrument powered on, place a 10Kohm resistor between Pin 1 and Pin 2. The display should give a reading of 25 degrees Centigrade.
If this is the case then assume the instrument is functioning correctly and the temperature error is due to a faulty transducer or cabling.
There is no calibration adjustment for the Temperature in the ST50 Speed. To see if there is a fault with the transducer assembly, do following test;
Disconnect the transducer cable from the display head and locate pins 1 and 2. You do this by facing the plug end of the instrument cable with the reference notch at six o'clock position, Pin 1 is at 7 o'clock and pin 2 is at 10 o'clock position. With the instrument powered on, place a 10Kohm resistor between Pin 1 and Pin 2. The display should give a reading of 25 degrees Centigrade.
If this is the case then assume the instrument is functioning correctly and the temperature error is due to a faulty transducer or cabling.
john_morris_uk
Well-Known Member
Did they change things from ST50 to the ST60 then? I certainly remember calibrating the temperature on our ST60 intruments. (I got the reading of the water temperature from a Hydrographic ship nearby so I was fairly confident that I was putting it to the right temperature!!)
iangrant
Well-Known Member
Guess they have, RAYMARINE say there's no calibration on the ST50.
earlybird
Well-Known Member
[ QUOTE ]
When did they change things from ST50 to ST60 then
[/ QUOTE ] Agreed, the ST60 does have a temp calibration function, but, interestingly, another difference is that the ST60 speed needs to "see" a temperature sender otherwise it thinks that it is a slave unit and will only display seatalk speed rather than direct transducer data. This caused me a lot of frutration when I fitted an ST60 unit, a Tridata, to an old ST50 paddlewheel with a defunct temp. sender. The agent didn't know this but a forumite did. The solution was to fit a resistor across the instrument terminals. I now sail in seas that never fall below 27 deg.!
When did they change things from ST50 to ST60 then
[/ QUOTE ] Agreed, the ST60 does have a temp calibration function, but, interestingly, another difference is that the ST60 speed needs to "see" a temperature sender otherwise it thinks that it is a slave unit and will only display seatalk speed rather than direct transducer data. This caused me a lot of frutration when I fitted an ST60 unit, a Tridata, to an old ST50 paddlewheel with a defunct temp. sender. The agent didn't know this but a forumite did. The solution was to fit a resistor across the instrument terminals. I now sail in seas that never fall below 27 deg.!
LadyJessie
Well-Known Member
I have the same problem. If your cables are OK, then it is the sensor in the impeller assembly that is broken. Seems to be a common problem and there is nothing to do except buy a new impeller assembly. As the log works fine, I decided that reading water temperature was not that important to me so I have not changed it.
iangrant
Well-Known Member
If the engineering solution is too trickey it's back to nature:
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