 # Calculation of the Expanded Uncertainty of the Measurements of the Moisture Content of a Lot of Paper Samples

Oven drying at 105°C was explored as a method for determining the dry matter content in the laboratory. It was used in this work to determine the moisture content of sheets and boards that did not contain any other chemical compounds save water. The moisture content of a paper sample is mostly determined by the moisture content of its environment.

The goal of this project was to expand on the ISO technique in the laboratory by employing four different paper substrates and statistically analysing the findings.

The proper sampling process, as well as the conditioning of the quality control sample paper, were given priority. The moisture content measurements were carried out in a 105oC oven for 16 hours.

The moisture percentage of the paper substrates studied was 4 percent -6 percent w/w, according to the analytical results. Finally, the moisture content was calculated as a percentage mass fraction using the equation wH2O=((mo-m1)/mo)x100 (1a)

where m0 was the mass of the test piece inside the glass container before oven drying or at the time of sampling, in grammes, and m1 was the mass of the test piece inside the glass container after drying to constant mass, in grammes. For the physical transformation of water into vapour, the definition of the standard enthalpy change was used.

In addition, the combined standard uncertainty was computed as follows:

(RSD rMETHOD2+((u(wH2O)/wH2O)2) RSDTOTAL=(RSD rMETHOD2+((u(wH2O)/wH2O)2) RSDTOTAL=(RSD rMETHOD2+((u(wH2O) (1b)

CV=sr x100/mean (1c) was also used to determine the RSD rMETHOD (repeatability coefficient of variation), where sr=repeatability standard deviation.

For each of the four separate samples of paper, the expanded uncertainty was computed using the equation: Uexpanded = 2.RSDTOTAL at a 95% confidence level and coefficient k=2 (1d).

The statistical analysis of the gravimetric approach presented was required in order to further refine the analytical method employed in the laboratory and thus produce exact results, as well as to quantify extended uncertainties and estimate moisture content expectations. The goal of the study was to quantify the uncertainty of measuring the moisture content of paper samples in the lab and to investigate the statistics of this measurement using mathematical models.

Author(S) Details

Katerina Chryssou
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece.

Maria Stassinopoulou
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece.

Eugenia Lampi
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece. Previous post Zinc Barium Oxalate Crystals Grown by Gel Method: A Spectroscopic and Thermal Studies Next post Determination of Three Detergent Products and Identification of Surface Active Agents by Infrared Absorption Spectra and a Reflectance Graph