Optical Dissolved Oxygen Sensors for Hygienic Applications
VisiFerm is the first 12 mm optical dissolved oxygen sensor with integrated opto-electronics, having the full functionality of a measuring device with self-diagnostics. It is steam sterilizable, autoclavable and CIP compatible. VisiFerm DO requires less maintenance than a classical oxygen sensor as it does not have a mechanically sensitive membrane or a corrosive electrolyte.

2-Wire Analog or HART to PCS Connections

Digital communication (Modbus) and ECS
Which VisiFerm is Best for My Application?
Sensor Type | Typical Connection Strategy | Primary Output | Secondary Output | Optional Output | Wireless (Bluetooth) | Temperature Compensation |
---|---|---|---|---|---|---|
VisiFerm mA | 2-wire analog (or HART) to process control system; no transmitter required | 4-20mA (2 wire) |
HART 7.0 (2 wire) |
-- | Integrated with sensor | 4-20mA Compensated in sensor; Temperature is HART variable |
VisiFerm RS485 | Digital communication to process control system (Modbus or analog connection) | Modbus RTU
ECS |
4-20mA (3 wire) |
Profibus, Foundation Fieldbus, or 4-wire 4-20 mA with Wi adapter | Optional with Wi Adapter | 4-20mA compensated in sensor; Temperature is Modbus variable |

Dissolved Oxygen for Hygienic Applications
The VisiFerm DO is designed to meet the demanding needs of hygienic applications in the biotechnology, bio pharmaceutical, and food and beverage industry.
- Standard 12 mm sensor shaft format
- Autoclave, CIP, and SIP compatible
- Electrolyte-free, eliminating contamination
- Constructed from FDA compliant, and USP Class VI certified materials
Do you know all the potential sources of DO measurement error?

Much has been written about different strategies for proper DO control. However, little information has been publicly available regarding optimization of the actual measurement accuracy and reducing common sources of process-related error.
Get Hamilton's whitepaper on potential sources of optical dissolved oxygen measurement error and ways to mitigate the impact.
Specific Applications
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App Note - Real-time Monitoring of DCO2 in Addition to DO
In this application note, the utilization of a DCO2-probe in addition to a DO-probe at Ostwestfalen-Lippe University of Applied Sciences and Arts, is briefly described using cell cultivation with varying stirring speeds to demonstrate the value added of inline dissolved gas measurement.
Resources
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Catalog - Process Analytics
Download the Process Analytics sensor catalog to learn about the complete offering of Hamilton process sensors and accessories. -
Brochure - BioPharma
Innovative solutions for process analytics in biotechnological and pharmaceutical industries. -
Brochure - Arc Intelligent Sensors
Arc Intelligent sensors offer a new way to connect to your process control system.
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What is the purpose of the Junction Box (Ref 10076282)?
The Junction Box (Ref 10076282) is a simple, low cost solution to connect sensor wiring to end-user wiring. It is designed to work with 24VDC 2-wire sensors such as the VisiFerm mA, VisiTrace mA, and VisiPro. -
Do optical DO sensors require flow to measure accurately?
No, optical dissolved oxygen sensors will measure accurately without the need for flow. This is a key difference between optical and polarographic measurement technology. Polarographic sensors consume oxygen as part of their electrochemical reaction thus should have constant flow moving past the sensor to maintain accurate readings. -
Does my optical DO sensor require calibration prior to usage?
All Hamilton optical dissolved oxygen sensors come with factory calibration; however, for best accuracy, it is recommended that calibration is performed prior to use. The factory calibration does not account for variations in atmospheric pressure or humidity which are often different based on location.
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Best Practices: Zero Point Oxygen Calibration
There are several methods to achieving a good zero point calibration of optical and polarographic DO sensors. This paper looks at each procedure in depth. -
White Paper: Measurement Challenges with Optical Dissolved Oxygen Sensors
Measurement of dissolved oxygen is a critical control parameter for optimizing cell growth in bioprocesses. Download this whitepaper to learn how to optimize measurement accuracy and reduce common sources of process-related error.

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