Macro 900 Operation Manual V3© 2013 Palintest Ltd. www.palintest.com Page 144 of 147become generally unreliable and unrepeatable (unless taken under ideal conditions) due tointerfering factors such as refraction from visible air bubbles and microscopic aeration.25.5. What is the Accuracy of the Optical Probes?All Optical Probes, with the exception of the Turbidity Electrode, employfluorescent measurement techniques. Interference from microbiological speciesand compounds which fluoresce at similar wavelengths and differences influorescence caused by temperature, ambient light and turbidity can all causeinaccuracies.Fluorescence measurement is ideal for researchers who are interested indetecting the presence or absence of a specific substance in reasonableconcentrations and measuring relative fluorescence changes that can be usedas an indication of increasing or decreasing concentrations.Fluorescence measurement techniques are not ideal for quantitativemeasurement and it is therefore impossible to specify an absolute accuracy.In order to obtain accurate results, data obtained with a fluorescentelectrode in the field must be post-calibrated with data from standardlaboratory analysis of grab samples acquired during the study.
