Uncertainty Measurement of Weighing Results from an Electronic Analytical Balance

Uncertainty of a measurement result is a major issue in all fields of measurement. Weighing is a critical step in any chemical laboratory and analytical methods. It's an important uncertainty sources in uncertainties measurement in an analysis. In this paper we tried to present the influence factors that affect in uncertainty measurement of a mass determination. Technical specifications of a balance such as: Readability, Repeatability, Non-linearity, Sensitivity Tolerance, Temperature Coefficient of Sensitivity and effects of environmental factors such as: air humidity, air pressure and air buoyancy were estimated. In the absence of some disturbance factor like water adsorption phenomena, evaporation, magnetic and electrostatic effects, the measurement uncertainty for an electronic balance in our laboratory is in the 10 -4 to 10 -3 range (100 to 1000 ppm).