4. Pressure scales

This chapter is dedicated to reference instruments, whether used by a national metrology institute, an accredited calibration laboratory or an industrial laboratory. In the current state of instrumental technology, the pressure balance is the only instrument, in the high-pressure field, that can materialize pressure from the basic quantities of the SI system, and disseminate it with the best possible level of uncertainty.

This chapter also deals with the multiplier, a technology transfer instrument derived from the pressure balance. It is associated with it in its use, enabling extrapolation of the pressure measured by a balance.