Electro-Chemical DevicesTriton TR8 TA sensor measures turbidity with a unique multi-beam optical assembly. The first light beam is a reference detector that compensates for changes in the LED light source caused by aging or other variables. The second light beam detects the short path length, which is best of high-concentration measurement. The third light beam measures the longer path length, which is best for lower concentrations. The sensor electronics constantly adjusts turbidity signal readings versus the reference detector for superior measurement accuracy. A built-in digital filter helps to suppress potentially interfering signals while self-monitoring diagnostics assure high reliability. The sensor assembly features a long-life, near-infrared LED light source (880 nm), and the 90-degree scattered light method in accordance with ISO 7027/EN 27027.   The sensor is factory calibrated in formazine, FNU (Formazine Nephelometric Units), and is plug-and-play ready for applications.  Two nonvolatile memory banks are also available onboard to store user-initiated calibration data. The sensor operates over wide measurement range with output available in multiple units:  0.000 to 9999 FNU, or 0.00 to 3000 ppm, or 0.0 to 3.0 g/l, or 0 to 20 percent. Features an error rate of less than 5 percent of reading with repeatability greater than 1 percent of reading.