Sterilizable pH Sensor Offers Long-Term Accuracy

Published on: 

Endress+Hauser’s Memosens CPS171D pH electrode for hygienic and sterile biopharmaceutical processing provides stable measurements even after multiple cleaning and sterilization cycles.

High yields and high quality product are achieved in fermentation applications with accurate and reliable pH measurement over a narrow range. The Endress+Hauser Memosens CPS171D pH probe has been developed with a unique reference gel and glass membrane. When combined, these new features improve long-term stability for reliable and accurate measurement, even after multiple clean-in-place (CIP) and sterilize-in-place (SIP) cycles. The sensor performs well after autoclaving at 284 °F (140 °C). These sensor characteristics, pressurized reference, and ion trap make the CPS171D uniquely designed for bioreactors, fermenters, and other hygienic and sterile applications.

The CPS171D measures 0­–14 pH and works in temperatures from 32–284 °F (0–140 °C). The electrode is IECEx and ATEX approved for use in hazardous locations; has IP68 protection and a TÜV certificate; and has FDA, United States Pharmacopeia , and International Organization for Standardization approvals for biocompatibility regarding cytotoxicity and bioreactivity. It is suitable for clean-in-place and sterilize-in-place operations, including autoclaving up to 284 °F.

The sensor provides maximum process safety and data security because of noncontact, inductive digital signal transmission to its cable for communication to the Liquiline transmitter. The inductive connection eliminates problems with measured values being distorted from moisture or terminals becoming coated or corroded in service.

Memosens technology allows the sensor to store measuring and operating data in the sensor including serial number, calibration date, number of calibrations, offsets, pH application range, number of calibrations, hours of operation under extreme conditions, and other information. Recording sensor data in the sensor itself enables predictive maintenance and makes it easy for asset management software, such as Memobase Plus, to facilitate lifecycle management.


This technology also simplifies replacement in the field, because the sensor can simply be replaced with another calibrated sensor, which will automatically transfer its data to the transmitter. Once the sensor has been connected, its calibration is used for the measured value. Calibration data are stored in the sensor, so the sensor can be calibrated and adjusted independently of the measuring point.

Source: Endress+Hauser