This device used to measure avarage diameter of wool whith transfering straight air current inside wool bunch. Regular wool which has not medula layer can be analysed with that device.
Especially It is suitable for combed slivers.In addition,greasy rovings can be analysed provided that if amount of greas is constant and calibrated.

STANDARDS : ISO 1136,ISO 2403, BS 3181-1, ASTM D1448