Using an LM35 temperature sensor with ADC-11

kris · Post by **kris** » Sun Sep 12, 2004 3:27 am

I am attempting to use an LM35 temperature sensor with an ADC-11 logger. The driver has been installed, however Picoscope will only give a continuous voltage out put of 0.66V, regardless of the temperature it is subjected to.

I think that the issue is that i am utilising the voltage source from the ADC-11 to power the LM35 and that this is not working. Does the voltage source need to be enable? and if so how is it done?

Regards,

kris

Sarah · Post by **Sarah** » Tue Sep 14, 2004 3:01 pm

Hi Kris

Thank you for your post.

I would advise using a voltage supply from elsewhere to power your sensor. The ADC-11 is not designed to give a voltage output.

A consideration you should also make is that the sensor you have gives an output resolution of 10mV per degree C, which is very low. Hence small changes in temperature will not been seen by the ADC-11 as it does not have a great enough resolution.

Hope this helps

Best Regards

Angel · Post by **Angel** » Sun Sep 26, 2004 5:16 pm

Hi.

kris, I have several LM35 connected to some channels of a Adc-11 10 Bits with an independent power supply of + -15V to feed LM35 and op amps to obtain greater resolution, very near 0.01º (1uV), although the measurement scale logically is narrowed (40ºC).

Without the amplification the resolution that I have perceived is approximately of 0.6ºC.