Hampshire Avon: Dissolved oxygen data collected at one minute intervals from five river reaches

Instream dissolved oxygen (DO) measurements were periodically downloaded from the logger. Records were filtered on the value of DO using an algorithm that first screened out records using a DO minimum envelope by day and then by using a smooth spline, comparing the smoothed spline value with the observed value and accepting those records that fell within a certain tolerance. This tolerance was adjusted according to the river site and also the month. All records are included in the final datasets, with a flag describing data quality for each record.