Hanna Instruments is a worldwide leader in the development of electro-analytical instrumentation. Their calibration and buffer solutions are some of the best in the industry. EC need not be calibrated as frequently as pH but we recommend calibrating values every 3-6 months if the EC meter is used a few times a month.
Conductivity solution 1413 ĩS / cm for calibration. Individual portions - and virtually always fresh & no contamination risk.