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Electronics => Beginners => Topic started by: Nexo on October 06, 2016, 04:20:24 pm

Title: Difference between a sensor's offset and the function generator's offset.
Post by: Nexo on October 06, 2016, 04:20:24 pm

Hello everyone!
I've been wondering what's the difference between a sensor's offset and the function generator's offset because the definition of the first one in Wikipedia is:

"If the output signal is not zero when the measured property is zero, the sensor has an offset or bias. This is defined as the output of the sensor at zero input."

But what I've read when learning how to use a Function generator is that offset is the voltage that you add to a signal.

Then I found this page: http://www.ni.com/white-paper/14860/en/ (http://www.ni.com/white-paper/14860/en/)
Read the offset part, please.

So, could you please help me to sink in this?

Thanks in advance!

Title: Re: Difference between a sensor's offset and the function generator's offset.
Post by: rstofer on October 06, 2016, 06:23:05 pm

Offset on sensors just happens.  Temperature, design, whatever; sensors often have some kind of offset.  Eventually, it gets removed; usually during conversion and often in software.

Signal generators, OTOH, probably don't have offset unless it is deliberately added.  In some cases, offset comes in handy.  Consider sending a DC coupled sine wave to a single power rail op amp.  One way or the other, the midpoint of the signal needs to be shifted up to midway between Vcc and Gnd of the op amp.  So, a little DC offset is added to the sine wave.

Good old algebra:  'y = mx + b' still rules!