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Topic: SEn118A2b Temperature Sensor help? (Read 3033 times) previous topic - next topic



I bought this sensor because it looks like the head can be submerged in water and get a reading. The big question I have is that it only has 2 leads...so I'm guessing one for PWR and one for GND. The only temperature sensors I've seen had 3 pins..like the LM35.

I'm confused as to how I can read temperature with this thing..any ideas?

Big Oil

I think it's a variable resistor, like a light sensor, which also has two wires. 
Here's a light sensor tutorial: http://www.ladyada.net/learn/sensors/cds.html with a wiring schematic halfway down under "analog voltage reading method"


According to the datasheet you linked, it's a resistor that varies it's resistance according to the temperature.

At -25 degrees C it has 133K ohms.

At 125 degrees C it has .3K ohms.

So, you hook it up voltage divider style to an analog input.

http://www.arduino.cc/playground/ComponentLib/Thermistor is a general hookup diagram, but this part has a 133K top resistance, and I can't figure out what the max current for it is.

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