Standard Calibration Solution Set for Apera Instruments White Light Portable Turbidity Meters (TN500 and TN420) AMCO Clear® turbidity standard solutions (20.0 NTU, 100 NTU, 400 NTU, 800 NTU). AMCO Clear® is an EPA approved primary standard for calibration of turbidity sensors that is safe, non-toxic and disposable. It is easy-to-use with no dilution or resuspension, and it is available in a wide range of values. The standards have a guaranteed one-year shelf life even if you've opened the bottle and happened not to have recapped it tightly. The convenient submicron polymer suspensions are non-toxic primary calibration standards approved by the US EPA for drinking water analysis for turbidity.

*Store at room temperature. Never freeze.