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Topic: Accurate resistence measurement without reference resistor? (Read 10121 times) previous topic - next topic

MrGarak

#15
Sep 20, 2012, 10:06 pm Last Edit: Sep 20, 2012, 10:12 pm by MrGarak Reason: 1
Docedison, I looked at the attached datasheet for the AD592, and it says it has an accuracy of +/- 0.5C and not 0.3c? So far it seems like the SHT75 is my best bet since it also measures humidity (whose accuracy is dependent on the temperature).

From an electronics standpoint, I was curious if I'm better off running cat5 to the sensors outside (which of course would be subject to the complications and limitations of the I2C standard) or if having a second arduino which would transmit serially over the cat5 is a better solution. My concern with a second uno outside is that the temperature changes to the uno board could affect the accuracy too. Also, two unos seems like overkill when it could all easily be done on one, but obviously I need that one inside so it can display information on an LCD screen. I would need to run a cable out regardless since the sensor measurement assembly needs to be fan aspirated to get accurate temperature readings.

Sorry for the wandering nature of this thread, if it's preferred perhaps a topic in the projects forum would be better suited to this discussion.

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