The laboratory vane apparatus is based on an original concept of the Transport and Road Research Laboratory of the United Kingdom. It can be provided with a wide range of vane sizes, although as standard, it is sold with the 12.7 mm square vane and a set of four calibrated springs. The test can be performed directly on the sample or in the sample contained in the sampling tube. In this case the NG-WF1736 Attachment for 38 and 100 mm dia. sampling tubes, should be used. See accessories.