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©2016, Industrial Test Systems, Inc. Printed in USA
NSF/ANSI 50 CERTIFICATION
Third-party certifi cation to NSF/ANSI 50 allows manufacturers to
make verifi ed claims regarding the performance, accuracy and
operating range of their water quality testing devices. It allows
consumers to make apples-to-apples comparisons between
different products and provides confi dence that the test device will
work at the end of the shelf life indicated by the manufacturer.
Third-party certifi cation of a water quality test devices includes
a review of water contact materials for health effects, monitoring
audit(s) of production locations and product performance
verifi cation testing. The performance testing of a WQTD involves
accuracy and repeatability testing on two different lots of new
production. The two lots are tested multiple times on two different
days. Unlike most NSF/ANSI 50 certifi cations, WQTDs require
follow-up testing of the product at the end of the manufacturer’s
specifi ed shelf life. This is a follow-up performance test on product
that has been opened and stored, in order to mimic actual product
use. The original two lots are retested for accuracy at the end of
the manufacturer’s claimed product shelf life. The accuracy testing
verifi es the water quality test device accuracy claim. Certifi ed
products are given an accuracy rating to one of three levels: L1, L2
or L3, with L1 being the highest accuracy rating.
TEST RANGE
ACCURACY RATING
Total Alkalinity 10 - 200 ppm
Calcium Hardness 3 - 700 ppm
Chloride 77 - 6700 ppm
Combined Chlorine 0.05 - 12 ppm
Free Chlorine 0.01 - 12 ppm L1
Total Chlorine 0.01 - 12 ppm
Cyanuric Acid 3 - 110 ppm
pH 6.4 - 8.4 pH L1
Total Alkalinity (SPA) 20 - 200 ppm
Total Bromine (SPA) 0.08 - 17 ppm L1
Combined Chlorine (SPA)
0.01 - 12 ppm
Free Chlorine (SPA) 0.05 - 12 ppm L1
pH (SPA) 6.0 - 8.5 pH L2