There Designed for portability and durability the Oakton WD-35635-05 T-100 Turbidity meter is ideal for monitoring turbidity in chemical, food and industrial applications. The microprocessor-based T-100 turbidity meter uses an infrared LED light source and delivers unprecedented repeatability and accuracy while offering resolution as low as 0.01 NTU. This lightweight meter is a valuable analytical tool for field-testing and quality control. Calibration standards are now provided in freeze-resistant 60-mL HDPE bottles for better shipping and longer shelf-life. The WD3563505 includes the meter and batteries.