Traditionally, in the cigarettes industry, the determination of ammonium ion in the mainstream smoke is performed by ion chromatography. This work studies this determination and compares the results of this technique with the use of external and internal standard calibration. A reference cigarette sample presented measurement uncertainty of 2.0 μg/cigarette and 1.5 μg/cigarette, with external and internal standard, respectively. It is observed that the greatest source of uncertainty is the bias correction factor and that it is even more significant when using external standard, confirming thus the importance of internal standardization for this correction

The objective was to analyze a recently developed flow measurement technique based on the vibration captured by an accelerometer attached to the pipeline surface for use in the oil industry. The applied methodology consists of performing an experimental study to obtain data in an accredited laboratory for calibration of flowmeters, estimating a flow rate for each vibration measured, followed by an uncertainty analysis. The results of water flow rates showed a measurement uncertainty between 2.5% and 5.0% of reading (95% confidence). While these results do not meet to Brazilian regulations for the measurement of crude oil of 0.3% of reading, they are acceptable under the regulations for produced, injected, captured, or discarded water, which occur the processing of oil.