If you collect data from automated sensors, occasionally those sensors foul causing a no data to be collected. Sometimes the sensors can partly foul such when collecting optical measurements such as water turbidity. What you observe in the collected data is a drift in the collected data over time. If you know when the fouling started and what the end data value should be, then you can attempt to correct the data by readjusting it to a new baseline. The Correct Data Drift function in Truii applies a simple linear correction to data.

Step 1. Select the data

The files that you have open will appear in a tree view on the left of the popup. You can only correct the drift in one column at a time. Select the column and then use the slider to select the range over which you wish to correct the drift. Define the end value. All values within the drift period will be linearly readjusted to achieve the defined end value.

Step 2. Method

The drift correction approach applies a linear correction for each cell. Truii determines the amount of adjustment required for each cell and then applies that across the range selected. Drift correction can only be applied to time series data – that is table data with a column of unique date/time values.

Step 3. Result

The default result is to overwrite the original file with the modified file. If you want to keep your original file, simply select either ‘Keep all Columns’ or ‘Keep only Selected Columns’ under the ‘Create new file’ in the output options. The new file will be saved in the same folder as the original file.