Is there an expiration date on the standardizing solutions?
Unopened with an unbroken seal, the solution will last one year. Opened, but placed in an airtight container, the solution will last six months. Opened and exposed to air, the solution will last one day. Note: Standards below 100 uS will degrade at a faster rate than others due to air. The conductivity of air is approximately 120 uS; any standard lower than 120 uS will slowly rise in conductivity until it reaches a state of equilibrium. Evaporation drastically increases conductivity values.
