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.

T500-1 Polymer AMCO Turbidity Standard Calibration Solution Kit

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.
We warrant this instrument to be free from defects in material and workmanship and agree to repair or replace free of charge, at the option of APERA INSTRUMENTS, LLC, any malfunctioned or damaged product attributable to the responsibility of APERA INSTRUMENTS, LLC for a period of TWO YEARS for the stirrer from delivery.

This limited warranty does NOT cover any issues due to:

Accidental damage

Improper use

Normal wear and tear

Transportation

Storage

Failure to follow the product instructions

Unauthorized maintenance, modifications, combination or use with any products, materials, processes, systems or other matter

Unauthorized repair

External causes such as accidents, abuse, or other actions or events beyond our reasonable control.