Noise floor of ScanAsyst

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BrukerApplications replied on Tue, Jan 12 2010 1:04 PM

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The offset tip used in HarmoniX should enhance the signal-to-noise ratio of the cantilever during tapping mode; since you went back to a more traditional probe do you create more noise in your measurements?

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Mike Maybrun replied on Wed, Feb 24 2010 1:33 PM

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 With HarmoniX signal to noise is an issue on the vertical deflection axis only at integer multiples of the tapping drive frequency but not at the feedback frequency.  The offset tip used in HarmoniX enhances the signal-to-noise at integer multiples of the tapping drive frequency on the lateral axis.   A complete spectrum of these harmonics are required to construct force vs. time plots.  Being able to detect them on the lateral axis is a key part of HarmoniX.

The height channel in a HarmoniX image is the result of Tapping mode feedback taken from the vertical deflection channel and the noise is approximately equivalent to a Tapping Mode image taken with a traditional probe of similar spring constant and resonance frequency.

The noise floor of a ScanAsyst height image is approximately the same as from a Tapping Mode or HarmoniX height image. 

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Mike Maybrun replied on Wed, Mar 17 2010 10:17 PM

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The noise floor of a ScanAsyst height image is approximately the same as from a Tapping Mode or HarmoniX height image. 

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