Naphthalene as a reference substance for vapour pressure measurements looked upon from an unconventional point of view

Naphthalene [CA 91-20-3] is a recommended reference substance for vapour pressure measurements. In this communication, data from several sources are brought together and assessed on the basis of a new type of representation. This representation is physical in nature and it reveals at a glance the precision of the individual sets of data and also the mutual consistency of the sets taken together. In this graphical representation an excellent set of data has the shape of an arc. For liquid as well as for crystalline naphthalene the available vapour pressure data are used to construct representative arcs, such that as much as possible justice is done to the complete collection of data. Use of the constructed arcs is recommended for testing the performance of vapour pressure instruments.