Microprocessor based turbidity meters that provide laboratory accuracy for field turbidity measurements. It is easy to calibrate (with 3 point calibration) using AMCO-EPA standards and is ISO 7027 compliant. Hanna instruments has chosen 10 FTU as the calibration point because it is the value that best fits the water turbidity measurements in different applications, from drinking water to wastewater treatment. Hanna instruments uses the primary standard AMCO-AEPA-1 to avoid all formazine-related problems. Formazine is a very toxic, unstable substance which requires particular care: its standards have to be prepared only a few minutes before performing the calibration, and cannot be reused because of their short life. Hanna AMCO-AEPA-1 standards are extremely stable, can be reused, and last up to six months if free from contamination. HI 93703 can be used with both standards. The HI 93703-11 enhanced version features a real-time clock, Logging for up to 199 measurements and PC compatibility via the RS232 interface and Windows compatible HI 92000 software. Both versions meet the requirements of GLP (Good Laboratory Practice) protocols for last calibration data storage. It is is supplied complete with glass cuvette, batteries and instructions. 0.00 to 50.00 FTU; 50 to 1000 FTU range. 0.01 FTU (0.00 to 50.00 FTU); 1 FTU (50 to 1000 FTU) resolution. +/-0.5 FTU or +/-5 percent of reading (whichever is greater) accuracy. 3 points (0 FTU, 10 FTU and 500 FTU) calibration. infrared LED light source. Silicon Photocell light detection. Measures 8-11/16" length by 3-3/16" width by 2-19/32" height.