KERN ABT-A01 Operating Manual

Contents

6 Preconditions for Precise MeasurementsThere are numerous error possibilities during density determination.Accurate knowledge and caution are required to achieve precise results whenapplying this density set in combination with the balance.6.1 Calculation of ResultsThe balance displays results for density determination by giving four decimal places.However, this does not mean that the results are accurate down to the last decimalplace as this would be the case for a calculated value. Therefore all weighing resultsused for calculations have to be examined closely.Example for density determination of solids:To ensure high-grade results, numerators as well as common denominators of theformula below must show the desired accuracy. If either of them is instable or flawed,the result, too, will be instable or flawed.ρ = AA-B oρρ = density of sampleA = weight of the sample in airB = weight of sample in measuring fluidρo = density of measuring fluidThe use of a heavy specimen contributes to the accuracy of a result because thisincreases the numerical value. The use of a light-weight specimen, too, contributes tothe accuracy of a result because this increases buoyancy (A-B). As a consequence,the result of the common denominator increases. Bear also in mind that the accuracyof the density of the measuring fluid ρo enters into the common denominator and,thus, has considerable influence on the accuracy of the result.The result for the density of the specimen cannot be more accurate than the leastaccurate of the aforementioned individual entities.This fact applies equally to the determination of density for fluids and glass plummetadjustment.38 ABT-A01-BA-defsi-0710