TURBIDITY METER The microprocessor-based waterproof TN100 meter is an easy-to-use turbidimeter that meets the rigor of rugged field applications. It is a " must -have " for anyone monitoring turbidity on the go. Using an Infrared light source, it delivers laboratory accuracy with a resolution of 0.01 NTU across an extended range of up to 20 NTU ( Nephelometric Turbidity Units) . Specifications Principle of Operation     Nephelometric non-ratio ( conformance to ISO 7027 and DIN EN 27027)  Turbidity Range     0 to 1000 NTU Resolution     0.01 NTU ( 0 to 19.9 NTU)  0.1 NTU ( 20.0 to 99.9 NTU)  1 NTU ( 100 to 1000 NTU)  Accuracy ± 2% of reading ± 1 LSD for 0 to 500 NTU ± 3% of reading ± 1 LSD for 501 to1000 NTU Repeatability     ± 1% of reading or ± 0.01 NTU No. of Calibration Points     4 points ( automatic)  Response Time     1, 000, 000 tests Light Source     Infrared-emitting diode ( 850nm wavelength)  Special Functions     Auto-Ranging; Self-diagnostic Power Requirements     4 x 1.4V batteries, > 200 hours Includes:  (4) primary standards (0.02, 20.0, 100 and 800 NTU) (2) empty cuvettes with light shield caps Silicone oil Lint-free cloth 4 AAA batteries Instructions Hard carrying case