Temperature in a reef tank

[me2003]

I am working on a arduino controller which uses a DS18B20 temp sensor. I also want to use a similar system to monitor temperature in my aquarium over time.
I have had many issues with temperature controllers, thermometers and digital thermometers in the past. Heater temperature controllers are some of the most
variable. I have found I need to create redundant systems to prevent a bad heater from over heating my tank.

I would be interested in how other people deal with temperature control and their experience with thermometer accuracy errors. Please post any data.
I am also interested if anyone graphs their reef temp over a day like in this article

http://www.advancedaquarist.com/2009/6/aafeature#section-2

I compared the DS18B20 temp sensor data to other temperature measurements and will post data soon.

 

[me2003]

-------------------------------- Temp1 test ----------------------------------

Arduino Waterproof DS18B20 72.95
Vernier Lab Thermometer
20 kΩ NTC Thermistor
Accuracy: ±0.2°C at 0°C, ±0.5°C at 100°C 72.9

YSI high-precision thermistor sensor. 73.0

Neptune Apex Temperature sensor 73.1

Omega 73.4 (23.0 C)

LabTherm 1 75.2 (24.0 C)

LabTherm 2 74

Labtherm 3 73

---------------------------- Temp 2 test ------------------------------------


Arduino Waterproof DS18B20 81.6
Vernier
20 kΩ NTC Thermistor
Accuracy: ±0.2°C at 0°C, ±0.5°C at 100°C 81.7

YSI high-precision thermistor sensor. 81.8

Neptune Apex Temperature sensor 81.7

Omega 82.04 (27.8 C)

LabTherm 1 82.4 (28.0 C)

LabTherm 2 82

Labtherm 3 82

CoralLife Digital Thermometer 80.2

 

[me2003]

Temp meters

 

[me2003]

Temperature probes setup in a cooler floating at ~same level

 

[johntan]

I'm going two years strong on my ds18b20 + arduino man. They're great. Since they're 1wire you can poll several in a row too if you don't trust one.

 

[me2003]

I have now tested two different DS18B20 temp probes and they both were in the ~ +/- 0.1 range of others quality temp sensor.