The results are presented of key comparison CCM.P-K2 that covered the pressure range 10 kPa to 120 kPa in absolute mode. Nine national measurement institutes participated in the comparison, which used a piston-cylinder assembly of 335 mm nominal effective area as a transfer standard.Whilst not all laboratories were found to be equivalent at all pressures, the larger-than-expected instabilities in the transfer standard precluded the ability to discriminate between participants' standards at a level needed to fully support the Calibration Measurement Capabilities table in the BIPM key comparison database.

This chapter contains sections titled: Modeling a sensor's interactions with its environment Researching the parameters of a given model Determining regression line coefficients Example of a polynomial relation A simple example Examples of multivariable models Dealing with constraints Optimizing the search for a polynomial model Bibliography

This paper presents a preliminary analysis for designing a force comparator to be used in the French watt balance experiment. The first stage of this experiment consists in a static equilibrium, by means of a mechanical beam balance, between a gravitational force (a weight of an artefact having a known mass submitted to the acceleration due to the gravity) and a vertical electromagnetic force acting on a coil driven by a current subject to the magnetic induction field provided by a permanent magnet. The principle of the force comparison in the French experiment is explained. The general design configuration of the force balance using flexure strips as pivots is discussed and theoretical calculation results based on realistic assumptions of the static and dynamic behaviors of the balance are presented.