REAL-TIME IN-SITU BIOMASS OD MEASUREMENT FOR BIOPROCESS APPLICATIONS
Trusted across a wide range of applications and scales, EXcell biomass probes have become the preferred solution for facilities requiring reliable, real-time biomass measurement, monitoring, and control. Installed directly into bioreactors and vessels, they deliver continuous in-situ data that supports every stage of the bioprocess lifecycle from discovery and process development through to full-scale manufacturing.
A key strength of the EXcell platform is its scalability. The same measurement technology is transferable across scale-up stages, providing consistency of measurement throughout the entire process and simplifying validation efforts. EXcell probes are fully compatible with in-situ sterilization (SIP) and cleaning (CIP) procedures, and are autoclavable, ensuring seamless integration into GMP environments.
Available in a compact 12 mm diameter format and in the standard DN25 "Ingold" port design — with multiple o-seal position options — EXcell probes offer flexible installation across diverse vessel configurations. A comprehensive accessories ecosystem supports system integration, including retractable housings, automated cleaning systems, local displays, and interfaces for connection to control and supervisory data systems. Probe setup and configuration is handled through the Exner EXpert PC software via USB.
All sensors are manufactured to surface quality standards appropriate for pharmaceutical applications, with full material certification meeting current hygiene regulations. All components satisfy FDA requirements.
Key Features
- Scalable platform - Same technology from lab to manufacturing; simplifies validation across scale-up
- SIP / CIP compatible - Fully autoclavable with resilient sapphire windows; hygienic design throughout
- Flexible installation - 12 mm and DN25 Ingold formats; retractable housings and local displays available
- GMP-ready - Full material certification, FDA-compliant components, pharma-grade surface quality
- Easy configuration - EXpert PC software via USB; liquid-free calibration with EXcap filters
- Connectivity – Range of accessories allows integration into any control system
The Exner EXcell Family of NIR Biomass OD Sensors
EXcell probes are available with a variety of insertion lengths, process connections and optical paths to allow ultimate flexibility when applying them to existing and new plants. Where installation fittings are needed, EXcell probes are fully compatible with the EXstatic and EXtract range of adapters and housings, ensuring that everything will fit and that hygienic properties will be maintained.
EXcell 231 NIR
EXcell 231 NIR Biomass Sensor
| Measuring Range | 0 to 6 AU / 0 to 6600 EBC |
| Resolution | 0.01 AU |
| Accuracy | ± 1 % |
| Reproducibility | ≤ 1 % from final value |
| Wavelength | 850 nm |
| Optical Path Length | 5 / 10 / 20 mm |
A NIR biomass probe with Pg 13.5 thread for direct and EXstatic/EXtract housing installation.
EXcell 241 NIR
EXcell 241 NIR Biomass Sensor
| Measuring Range | 0 to 6 AU / 0 to 6600 EBC |
| Resolution | 0.1 % or 0.01 AU |
| Accuracy | ± 1 % |
| Reproducibility | ≤ 1 % from final value |
| Wavelength | 850 nm |
| Optical Path Length | 5 / 10 / 20 mm |
A NIR biomass probe DN25 port fitting for direct installation.
EXCAP CALIBRATION SETS
Make the calibration checking and verification of EXcell probes liquid free using EXcap solid state calibration reference standards. EXNER calibration standards are available with a range of different values to ensure probes are working to specification.
To use, EXcaps are simply applied to an instruments’ process interface to simulate a known and repeatable measurement response. EXcaps are supplied in a protective case with each being permanently marked with its simulation value. All EXcaps are supplied with a calibration certificate and Exner offers a recalibration service for periodic recertification.
EXcap 110 (absorbance)
EXcap 110 calibration references are designed for use with Exner optical instruments that use NIR absorbance as their measurement technique. The EXcap 110 range includes seven values. Sets are supplied in a protective carrying case with up to three individually selected filters to enable verification of instruments in their applied measuring range.
| Reference Type | Absorbance |
| Available Values | 0.35 AU / 55% turbidity 1 AU / 90% turbidity 2 AU / 99% turbidity 3 AU 4 AUv 5 AU 6 AU |
| Carrying Case Dimensions | 120 x 116 x 40 mm / 4.7 x 4.6 x 1.6” |
BIOMASS OD PROBE INTERFACE ACCESSORIES
Exner offers a flexible range of interface and control accessories for the EXcell biomass sensor, allowing it to be deployed effectively from simple lab setups through to fully integrated process environments. The ECI-01 is a USB converter designed for direct connection to a PC, working with the EXpert software to configure operating parameters, establish correlations between raw sensor output and meaningful process units, and provides data logging and trending.
For industrial integration, the ECI-02 provides a DIN rail-mounted interface that converts the sensor signal to Modbus over RS485, allowing seamless connection into PLCs, SCADA systems, or plant-wide control networks. The ECI-03, housed in a compact 1/8 DIN enclosure with an integrated touchscreen, offers local display along with analog and status outputs for direct connection to control systems.
All three interface accessories supply power to the EXcell sensor, simplifying installation and reducing the need for additional hardware.
ECI-01 USB Interface
The ECI-01 is a compact USB interface designed for direct connection of the EXcell sensor to a PC. Used in conjunction with the EXpert software, it enables full sensor configuration, signal correlation to engineering units (e.g., AU to mg/L), and real-time data logging and trending. Multiple units can be connected to a single computer, making it ideal for laboratory and multi-channel applications.
| Connection | USB plug |
| Dimensions | 80mm x 23 mm diameter |
| Cable length | 2m / 6.6ft |
ECI-02 R485 Serial Interfae
The ECI-02 is designed to digitally connect EXcell sensors into an external system. It converts the EXcell sensor output into Modbus over RS485 for seamless integration into PLC, SCADA, or distributed control interfaces. Built for industrial environments, it provides a straightforward path to incorporate real-time biomass measurement into existing automation architectures.
| Power Supply | 24Vdc (12…36Vdc) |
| Mounting | 23mm DIN Rail |
| Dimensions | 46 x 50 x 11mm |
| Output | Modbus over RS485 |
ECI-03 Display/Analog Output
The ECI-03 is a 1/8 DIN panel-mounted unit with an integrated touchscreen display for local indication and control. It provides analog and status outputs for direct connection to plant systems, enabling operators to monitor biomass levels at a glance while supporting simple integration into local control loops.
An ECI-03 connected to an EXcell sensor provides:
- Power for the EXcell sensor
- Local Display
- Analog Output (0/4…20mA)
- Alarm Status Contact
- Adjustable Limit Contact
The unit features a touchscreen to access setup parameters and output ranging.
| Enclosure Size | 48 x 95.8 mm (1/8 DIN) |
| Power Supply | 24Vdc (12…36Vdc) |
| Display Size | 25 x 29mm (Touch Screen) |
| Output | 0/4…20mA |
| Limit Contact | 24Vdc, 100 mA |
| Alarm Contact | 24Vdc, 100 mA |
EXpert Configuration Software
EXpert is a powerful and intuitive configuration software for use with Exner optical NIR sensors, including the Excell, EXpure, and EXspect models. Connecting directly to a Windows PC via USB, the software provides a real-time measurement dashboard displaying current values, temperature, and switching states in a dynamic time-based graph. With support for a wide range of measurement units including, amongst others, AU, OD, EBC, NTU, and mg/L, EXpert gives engineers and process technicians the flexibility to monitor and record data in meaningful units relevant to their application. Continuous .csv data logging ensures that measurement histories are always captured and available for further analysis.
EXpert offers a comprehensive suite of signal processing and calibration tools to ensure accurate, stable measurement output. Users can apply moving-average damping, noise reduction, and a configurable level of detail to smooth unstable signals caused by factors such as air bubbles or process turbulence. The software also supports full user-defined calibration (CDU) using up to 10 calibration points, allowing sensors to be configured for virtually any measurable quantity without affecting the preserved factory calibration, which can be restored at any time.
Beyond measurement and calibration, EXpert provides complete control over sensor configuration, including analog current output (0–20 mA or 4–20 mA), digital switching outputs with configurable hysteresis or window functions, and Modbus communication settings. Parameter profiles can be saved to file and loaded onto other sensors of the same type, making fleet-wide configuration straightforward. Firmware updates to the sensors can be applied directly through the software while preserving all user settings, ensuring sensors stay current with minimal downtime. With its two-tier access control system and a clean, tab-based interface, EXpert is a reliable tool for both day-to-day monitoring and advanced sensor management in demanding industrial environments.
Key features of the EXpert software include:
Measurement & Display
- Real-time display of measured values, temperature, and switching state in a time-based graph
- Adjustable time base for recording intervals
- Support for multiple measurement units: AU, OD, EBC, CDU, TEF, FAU, %, mg/L, NTU, FNU
- Higher resolution mode (10x factor increase)
- Graph reset functionality
Offset & Zeroing
- "Set to Zero" function to define baseline at any point
- Manual offset entry (positive or negative) to correct against a reference value
- Offset on/off toggle with active offset indicator in the measurement view
Signal Damping & Smoothing
- Damping of the measurement (moving average, up to 100 values)
- Temperature damping
- Noise reduction (mathematical interference filter)
Calibration (CDU)
- User-defined calibration using 2–10 calibration/correlation points
- Custom unit naming
- Factory calibration preserved and restorable at any time
- Save/load calibration profiles to/from file
Configuration
- Analog current output (0–20 mA or 4–20 mA, min/max/error values)
- Digital switching output (ON/OFF levels, window or hysteresis mode, switch function, switching delay)
- Modbus settings (address, baud rate, parity, service access code)
- Save/load parameter profiles to/from file
- "Clone" sensor settings to other sensors of the same type
Data Logging
- Continuous export of measured values to .csv file
- Selectable data fields: date/time, temperature, switch status, AU, EBC, CDU, OD, TEF, FAU, mg/L, error/warning bits
Firmware Management
- Sensor firmware update
- User settings and calibrations are preserved during updates
Sensor Information & Management
- Sensor ID view (PCB version, firmware, serial number, type, tag)
- Sensor TAG number entry
- Status monitoring with error and warning indicators
Access Control
- Two access levels: "Free" (read-only) and "Service" (full access – password protected)
- Language selection
Have more questions? Take a quick moment to get in touch with our expert sales engineers and technologists and we'll guide you to a solution.
No matter the application or industry, South Fork Instruments can develop a superior optical sensor-based measurement solution.
We have provided NIR optical sensor solutions to clients in such industries as food and beverage, chemical processing, pharmaceutical manufacturing, and biotechnology, and can assist you in developing and effective and efficient means of fulfilling your measurement needs.
SOUTH FORK INSTRUMENTS
3845 Buffalo Road
Auburn, CA 95602
Tel: (+1) 925-461-5059
