Quaternary Ammonia Test Paper  (90 second test) with readings at 100, 200, 400 ppm sold by the dozen (CLICK ON PICTURE TO GO BACK) Copyright Precision Laboratories 2006. Tel: + 44 (0) 1553 841513   Fax: + 44 (0) 1553 841513    Email: sales@precisionlabs.co.uk Website: www.precisionlabs.co.uk