Hanna Instruments 12880 μS/cm Conductivity Standard (500mL Bottle) HI7030LHI7030L is a premium quality 12,880 S cm conductivity standard that is prepared against a NIST traceable potassium chloride solution. Hanna conductivity solutions have the lot number and expiration date clearly marked on the label and are air tight with a tamper proof seal to ensure the quality of the solution. Hannas line of conductivity standards have been specially formulated to have an expiration of 5 years from the date of manufacture for an