It consists of a steel tube in which a resin bonded core is baked. One solid rubber stopper closes one end of the tube while the other is closed with a rubber stopper containing a desiccator to keep the core dry. It may be used to check permeability readings obtained by either the orifice or by stopwatch method. Also, readings obtained from direct reading permeability meters can be checked.

Standards are made in two permeability ranges: order No. 352-S for the small range (30) or No. 352-L for the large range (100).

Specifications:

Net weight 1 lb. (0.45 kg)