Hamilton Bioprocess pH Sensors (EasyFerm Plus, EasyFerm Bio and OneFerm)

Hamilton EasyFerm Plus, EasyFerm Bio and OneFerm are pH (and ORP) sensors for bioreactors, fermentation and single-use bioprocess lines. EasyFerm Plus and Bio are autoclavable and compatible with SIP and CIP over 0 to 140 °C and up to 6 bar g; OneFerm is the single-use version for bags and disposable bioreactors. A pre-pressurized Everef-F reference with Phermlyte or Foodlyte electrolyte and a clog-free HP Coatramic diaphragm increases stability and accuracy and extends sensor lifetime. As one of Hamilton’s distributors in Turkey, Mikron Proses (Üsküdar, Istanbul) supplies these sensors and provides application consulting on sensor selection and ArcAir calibration setup.

Need a pH sensor for a bioreactor or fermenter? → Send us your requirement

See also the bioreactor pH sensor selection guide, the CIP and SIP guide and Hamilton pH and ORP process sensors.

Bioprocess pH sensor families compared

Series	Measuring range	Temperature / pressure	Electrolyte / diaphragm	Output	Typical use
EasyFerm Plus	0 to 14 pH	0 to 140 °C / 0 to 6 bar g	Pre-pressurized Phermlyte / HP Coatramic	Arc, Memosens, VP, S8, K8	Bioreactors, industrial processes
EasyFerm Plus ORP	± 2000 mV (Arc: ± 1500 mV)	0 to 140 °C / 0 to 6 bar g	Pre-pressurized Phermlyte / HP Coatramic	Arc, S8	Bioreactors, downstream processes
EasyFerm Bio	0 to 14 pH	0 to 140 °C / 0 to 6 bar g	Pre-pressurized Foodlyte / HP Coatramic	Arc, Memosens, VP, S8, K8	Bioreactors, brewhouse, downstream, gelatine manufacturing
OneFerm pH	3 to 10 pH	4 to 50 °C / 0 to 1 bar g	Single-use design	VP6 or K8, plus Arc Module SU pH (REF 243233)	Single-use bioreactor bags, rigid containers, mixers and downstream

Design features

Pre-pressurized reference and HP Coatramic diaphragm. Pairing the Phermlyte electrolyte with a pre-pressurized reference and the clog-free diaphragm increases the stability and accuracy of readings; the pre-pressurized electrolyte in the ORP version prevents the diffusion of sample into the sensor. Hamilton states that this gives extremely low drift over the sensor lifetime.

PHI and HB glass. Both glasses are developed to withstand frequent steam sterilization, autoclaving and CIP with hot caustics. Choose PHI where chemical robustness matters, and HB where a fast response time is needed.

Foodlyte. The reference electrolyte of EasyFerm Bio is based on food ingredients and was developed for the biotechnology, pharmaceutical and food industries.

OneFerm. OneFerm sensors are designed for single-use pharmaceutical and biotechnology applications. The reusable Arc Module SU pH (REF 243233) sits between the VP head of the sensor and the VP cable and converts the signal to two 4-20 mA signals (pH and temperature) or a Modbus signal; the temperature element is the pH Insert T (REF 10155128).

Digital integration. The Arc version carries a micro-transmitter in the sensor head and is managed with ArcAir, see the Arc peripherals and ArcAir page. Memosens versions connect to existing Memosens infrastructure. For related bioreactor sensors, see the CO2NTROL dissolved CO2 sensor and the InCyte and Dencytee cell density sensors; calibration solutions are on the DuraCal buffer page.

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Which sensor, glass and connector fit your reactor depends on the sterilization regime, the reactor type and your control system. Tell us about your bioreactor and we will help you choose.