The table below describes the Hydrolab H20 sensor maintenance for this month. It reports the dates that a specific H20 unit was deployed at the DO station, duration of deployment, and post-calibrated difference in each instrument. The DO calibration measurements are performed as air calibrations as described in the Hydrolab Corp., H20 manual. The differences listed are the changes in readings, before and after the Hydrolab units were serviced. Station service records for April, 1999.
Values given are differences between instruments before and after service.