HI7031L/C is a premium quality 1,413 µS/cm conductivity solution standardized with a conductivity meter that has been calibrated with potassium chloride NIST 2202 SRM (Standard Reference Material) in deionized water for analytiCalibration use in accordance with ISO 3696/BS3978. Additional equipment used in preparation of the solutions include certified weight-Checked balances, Class A glassware and certified thermometers.