The Extech TB400 is a portable, battery-operated turbidity meter that measures fluid clarity in Nephelometric Turbidity Units (NTU) from 0.00 to 1000 NTU with 0.01 NTU resolution. Compliant with ISO 7027, it uses an 850nm LED light source and requires only 10mL sample volume. Ideal for municipal water, food/beverage, and environmental testing—complete with calibration standards, test bottles, and hard case for field use.