Calibration of conductivity sensors in water (pharma)
Calibration of conductivity sensors in water for pharmaceutical applications
The various international pharmacopoeias (USP, EP, JP, etc.) impose strict standards on inline conductivity measurement for water in the pharmaceutical industry (such as PW, UPW and WFI). Conductivity is one of the most important parameters in determining water quality. It is only logical that you need to demonstrate that the measuring device you use is accurate, reproducible and can detect very small changes in conductivity. No need to worry though, ELSCOLAB can help you with periodic calibration.
Harmonised standards
Each country or region has its own pharmacopoeia. Fortunately, these are (nearly) all aligned in so-called harmonised standards. Chapter <645> of the USP contains all the guidelines and requirements for conductivity measurements, which also apply in other parts of the world.
The USP requires the measured conductivity to be displayed uncompensated (without temperature compensation). The resolution of the measuring device should be 0.1µS/cm. The cell constant (calibration parameter) of the sensor should be accurate to within 2%. The European Pharmacopoeia (EP) still states, among other things, that the measuring device should be calibrated with certified precision resistors (+/- 0.1%). The built-in temperature measurement should also be accurate to within 2°C.
Every pharmacopoeia states that the measuring system should be calibrated "periodically". The frequency thereof is left to the companies themselves, however. Generally, annual calibration is accepted, but more frequent calibration may be required.
The only digital calibrator
A complete measuring system for conductivity measurements that consists of an M300-ISM or an M800-ISM transmitter and UniCond ISM sensors from Mettler-Toledo-Thornton, calibrated with a UniCond calibrator with precision resistors (NIST traceable) is currently the only available digital system that is fully compliant with international requirements.
The UniCond calibrator allows you to perform inline calibrations without interrupting the pharmaceutical water system. The Thornton 1885 Field Calibration Kit is most suitable for calibrating the cell constant of UniCond sensors according to pharmacopoeia.
Assurance through certified equipment and certified technicians
ELSCOLAB offers a calibration service that meets all requirements, in full compliance with international pharmacopoeias.
- Simultaneous connection of the UniCond sensor and the M300/M800 transmitter without having to remove the sensor from the piping system.
- Use of precision resistors that are traceable to international standards (NIST).
- Pre-calibrated ISM (Intelligent Sensor Management) sensors can quickly replace deviating sensors to minimise downtime.
More information?