# Direct measurement

Schematic representation of the static air flow resistivity measurement apparatus presented in [ISO 9053].

# Issues & alternatives

The direct measurement is difficult for sample with low resistances (resistivity $\times$ thickness of the sample).
Alternative methods have been developed in such cases, for low intrinsically low resistivity materials [OPT02,PO06] or materials only provided with low thicknesses (such as facing screens) [JB11].