Hello people!

I have a simple problem(or difficult) which I cannot solve

When I hook up the Function Generator 33250A with the Oscilloscope MSO5034A, say my input is AC 1 Volt Sine wave, I can see that on my oscilloscope it fluctuates a little bit. I can reduce it by using the averaging function in the Oscilloscope but I cannot eliminate the fluctuation.

The reason why I want to fix this is because I need to do a repeatable test and it is very sensitive to small changes so this fluctuation would give me different result on a single experiment every time.

Is there a function which can 100% eliminate the fluctuation? or a statistical method which I can code up? I've been trying to work on this for a week and still no answer Please help a poor guys out..

-Sam

I have a simple problem(or difficult) which I cannot solve

When I hook up the Function Generator 33250A with the Oscilloscope MSO5034A, say my input is AC 1 Volt Sine wave, I can see that on my oscilloscope it fluctuates a little bit. I can reduce it by using the averaging function in the Oscilloscope but I cannot eliminate the fluctuation.

The reason why I want to fix this is because I need to do a repeatable test and it is very sensitive to small changes so this fluctuation would give me different result on a single experiment every time.

Is there a function which can 100% eliminate the fluctuation? or a statistical method which I can code up? I've been trying to work on this for a week and still no answer Please help a poor guys out..

-Sam

What you are seeing is noise. Noise is everywhere, in everything, and in every measurement. Some of what you are seeing is from the function generator. It's good but not perfect. Some is from the environment and/or cabling. Some is from the scope.

You should look at the specifications for the function generator and the scope. Look especially at the noise information. Remember that both are gaussian in shape, so you can add them using the square root of the sum of the squares.

While you are at it, look up the specifications for other function generators and signal generators, as well as for other scopes. In general, the more you spend on a tool, the better the specifications will be.

One of the most common ways of reducing measurement noise is, as you have discovered, averaging. If you have a repetitive signal, you can take multiple measurements and average them. The noise will go down approximately as the square root of n, where n is the number of measurements.

Now you can go back and work on the rest of your homework...