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Topic: Newie-Magnetic field measurements (Read 4326 times) previous topic - next topic


Hi there!

I'm a physicist (not experimental though), and I would like to begin constructing a Teslameter. The problem is that I don't know how much precission in the measurments could I get with arduino and the availiable Hall proves I have found on the internet. Furthermore, most of Hall proves work with 12 V voltage supply and I think arduino only provides 5 volts at maximum.

Can anybody tell me how could I construct a precision Teslameter able to measure up to 1Tesla or so? which hall prove should I buy?
Do I need more than one hall effect sensor to make measurements of mili-Tesla?
Can I add a power supply to arduino to work with more voltage?

Thank you in advance!


Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)


Some of the sensors magneto-resistive.
Look for HMC5843 on SparkFun, data sheet gives info in gauss, sensitive to micro-Tesla.
Or google for more data (sensitivity, range, precision), there are a lot of different species.
Search pattern: "magnetometer" or "magnetoresistive magnetometer"


No... you can't feed your Arduino a higher voltage... but the values from the Hall sensor can be scaled to 0 to 5v with some simple external components, if need be... or just get one which is happy to work on 5v.

Sounds like you want a "proportional" or "analog" (same thing) sensor. There are "digital" ones out there, too.


Keep in mind that measurement resolution and measurement range are two different aspects of a measurement. Resolution will be limited by the 10 bit A/D hardware which allow for 1024 steps of measurements. The range of the measurement is determined by the sensor used and that range can always be scaled up or down to match the arduino 0-5vdc measurement range.

So only you and the sensor you select can determine the measurement range you will end up with. Within that range the arduino can only discriminate it to one of 1024 possible values.


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