Conductivity Standards for Sensor Calibration – Accuracy, Stability and ISO 17034

Conductivity standards are reference solutions used to calibrate conductivity measuring instruments and ensure accurate, traceable measurement of a solution’s ability to conduct electrical current. Conductivity is directly related to the concentration of ions in a solution and is a critical parameter in industries such as water quality monitoring, pharmaceuticals, food production, and chemical processing.

Low-conductivity calibration standards are particularly sensitive and have traditionally been difficult to maintain because CO₂ absorption from the air can alter their conductivity values after opening. Hamilton addresses this challenge with a unique approach. Our glycerin-matrix formulation significantly enhances stability and provides guaranteed long-term performance for up to 3 years. Even when bottles remain open for up to one hour, Hamilton standards retain their documented stability and shelf life, ensuring reliable performance under realistic laboratory and field conditions.

Our glycerin-based standards, supplied in 250 ml glass bottles, offer long-term stability, minimal evaporation, and improved resistance to microbial growth. This ensures consistent and highly reliable performance over extended storage periods. For routine applications, our water-based Basic Line standards in 500 ml DuraCal bottles provide low viscosity for easy handling and minimal air bubble formation, combining practical usability with high measurement precision.

Hamilton is the first manufacturer to certify ISO 17034 conductivity standards at 1.3 µS/cm and 5 µS/cm standards with ±1% accuracy and documented shelf life. All standards are independently verified by leading European metrology institutes (DFM, ZMK), ensuring that low-conductivity measurements remain precise, traceable, and fully defensible. 

What makes ISO 17034 certified conductivity standards different from conventional conductivity solutions?

ISO 17034 certified conductivity standards are produced as certified reference materials with assigned values, defined measurement uncertainty, and documented traceability to recognized standards. For low‑conductivity ranges, this is particularly important, as small variations can significantly affect measurement results. ISO 17034 certification confirms that stability, homogeneity, and uncertainty have been evaluated over the product’s stated shelf life.

For a detailed explanation of certification, traceability, and measurement uncertainty for calibration solutions, see our ISO 17034-Certified liquid solutions article. We have detailed best practices for handling and storing conductivity standards, including managing temperature effects, in our article on calibration solution stability.

Related Content

• Download our Liquid Solutions Brochure to see the entire conductivity standard product offering.
• Learn more about the stability and accuracy of conductivity standards.
• Visit our Main Calibration Knowledge Base Page to see all articles on calibration solutions.