In this work one does a metrological analysis of the associated uncertainties to the kitchen oil density measurements using two different methods: the direct measurement (ratio mass-volume) and U tube method. The idea is to help the teacher in the setup of low cost experiments. About the measurement using the U tube method, improvements are proposed substituting the U glass tube for a low cost transparent flexible tube. The authors define the profit factor of an experiment, Fv, as being the product of the uncertainty in the physical quantity (δ) by its cost (C). The profit factor can be used as a criterion to decide between the quality of the obtained results and the cost of an experiment.
metrology; oil density; inexpensive experiment