OneFerm single-use pH sensors mimic standard, reusable process pH sensors. Hamilton offers products that output traditional analog (millivolt) pH signals. Some of these sensors are also fully integrated with Arc intelligent sensor technology.
This article explains the differences between OneFerm pH sensors and how to differentiate these sensors based on application.
Traditional OneFerm pH Sensors
Image Credit: Hamilton Process Analytics
Traditional OneFerm sensors with the K8 electrical connector provide a millivolt output signal compatible with most bioreactors and transmitters. This sensor does not have temperature compensation, so the input device requires a secondary dedicated temperature input or a manual temperature setting (that can be entered by the operator).
These products are suitable for existing bioreactor controllers that are being modified for single-use processing. Hamilton provides numerous adapter cables to interface with various devices.
Traditional OneFerm pH Sensors with Temperature Compensation
Image Credit: Hamilton Process Analytics
Traditional OneFerm sensors are also available with integral temperature compensation. Temperature elements involve both PT100 and PT1000 alternatives. These two forms of temperature elements are two-wire RTDs. A VP6 electrical connection is utilized due to the extra connections needed for temperature compensation and the millivolt signal.
The inclusion of temperature compensation means that these sensors are suitable for direct wiring into transmitters or when an unrelated temperature element cannot be easily utilized for compensation of the pH measurement.
Arc OneFerm pH Sensors
Image Credit: Hamilton Process Analytics
Arc OneFerm pH sensors are manufactured to work with the Arc Single-Use pH Module (Ref 243233). The sensor has similar functions to a reusable Arc pH sensor – the main difference is the detachable electronics module.
The module functions like a transmitter. It is completely reusable and remains with the bioreactor. The pH sensor is pre-installed and pre-sterilized with the bag. After the module and sensor are coupled, the sensor calibration data should be scanned into the module utilizing the ArcAir software.
Arc OneFerm single-use pH sensors have a similar appearance to traditional sensors with the VP connector. They are recognizable by the NTC temperature compensation element. These products are often found on newer bioreactors that enable 4 to 20 mA or Modbus digital protocol signals directly into the controller.
This information has been sourced, reviewed and adapted from materials provided by Hamilton Process Analytics.
For more information on this source, please visit Hamilton Process Analytics.