I would like to monitor temperature in an oven to check if temperature is homogeneous in the hot volume.
I have bought 5 LM335A sensors and an Arduino2009.
With one LM335A, the wiring is easy : On the Arduino 5V pin, i wire a 1kOhms resistor then the LM335A positive, then the LM335A negative pin, then the ground. The LM335+ pin is on the analog1 entry. => Everything looks fine, temperature seems OK.
I add the 5 LM335A in parrallel on the 5V Arduino pin and : 1. Intensities are high (as the total resistor is low). 2. The signal of the LM335A is constant even if I heat them. I tried to compute an equivalent resistance and adjust the resistor values (set them higher) but although the tension changes, the temperature value is wrong.
I guess there is an electronic problem behind this, but I can not figure out what is the cause.
Does it means something for you ? Anyone faced this problem ? In other words, is it stupid to try to wire 5 LM335A in parrallel on the 5V power supply ? Do I need to have separate 5V power supply ? Is it possible to use 5 lm335A on an Arduino2009 ? If no, why ?
Thanks for your help.