Adjust dynamic range of sensor


hello everyone,

first of all, first post in forum , i'm pretty new in amazing arduino world... forgive if problem has well-known solution (i couldn't find it).

i measuring output of temperature sensor (ds18b20), sending through serial port, , catching+plotting python. (using  arduino uno btw)

the problem following: range of temperatures sensor measuring output between +0.6v , +0.8v.
this means although analog-to-digital converter works @ 10-bit (1024 voltage levels), because 0v corresponds 0 , +5v corresponds 1023, 40 levels available signal...

this not nice.

so, question following: how can amplify/rescale 0.6-0.8v signal 0-5v?

i believe might problem many other sensor implementations, ask kind of circuit (using operational amplifiers, transitors.. etc.) assemble readjust output of kind of sensor. of course setting analog-digital converter work @ more resolution not point of question.

i believe can amplify output of sensor transistor, found ac amplification...and feel wouldn't work. friend suggested using op amp (in fashion: http://labjack.com/support/ue9/users-guide/2.7.3.5), if signal between 4.7-4.8 v, how rescale to  0-5v then? circuit multiply signal...

i want understand options solve problem. help!

the simplest thing use analogreference(internal) 1.1v.  give 5 times resolution.

a "textbook" amplifier made op-amp , 2 resistors amplifies ac , dc.   with op-amps make amplifier boost signal, plus summing amplifier add negative bias signal allow voltage go down zero.   

note there noise , inaccuracy in temperature measuring device (and op-amps generate noise) there's limit how more useful resolution/accuracy can amplification.


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