Differentiating Data

AES data can be differentiated manually or automatically. AugerScan uses the Savitzky-Golay algorithm to differentiate data.

To manually differentiate data, simply select the Differentiate command from the Data menu. (You can determine how many points are used to differentiate data by selecting the Options command in the Data menu.) Data that is manually differentiated is “transformed”. Therefore, you can select the “Revert to Raw“ command from the Data menu to undo the differentiation.

Automatic differentiation is available only if you are using a Model 21L and a lock-in amplifier to acquire lock-in data. To specify that you are acquiring lock-in (differentiated) data, select the Lock-in check box in the AES Hardware Properties dialog box (accessed through the System menu). You cannot undo the differentiation of automatically-differentiated data using the “Revert to Raw” command.

Use the Smooth command from the Data menu to smooth data after you differentiate it to remove noise.