Hanna Instruments HI 83214 Instruction Manual

4PRINCIPLE OF OPERATIONAbsorption of light is a typical phenomenon of interaction between electromagnetic radiation and matter.When a light beam crosses a substance, some of the radiation may be absorbed by atoms, molecules orcrystal lattices.If pure absorption occurs, the fraction of light absorbed depends both on the optical path length through thematter and on the physical-chemical characteristics of substance according to the Lambert-Beer Law:-log I/Io = ελ c dorA = ελ c dPRECISION AND ACCURACYPrecision is how closely repeated measurements agreewith each other. Precision is usually expressed asstandard deviation (SD).Accuracy is defined as the nearness of a test result tothe true value.Although good precision suggests good accuracy, preciseresults can be inaccurate. The figure explains thesedefinitions.For each method, the precision is expressed in therelated measurement section.SPECIFICATIONSLight Life Life of the instrumentLight Detector Silicon PhotocellEnvironment 0 to 50 °C (32 to 122 °F);max 90% RH non-condensingPower Supply External 12 Vdc power adaptorDimensions 235 x 212 x 143 mm (9.2 x 8.34 x 5.62")Weight 1.5 Kg (3.3 lb)For specifications related to each method (e.g. range, resolution etc.) refer to the related measurementsection.