Non-Invasive pH Sensors

Pre-calibrated, ready-to-use & real conditions: Look into any transparent vessel

Non-Invasive pH Sensors in Cell Culture Flasks
  • Variety of disposables
  • Bags & single-use bioreactors
  • Micro-liter to production scale

The non-invasive pH sensors are optimized for physiological solutions and culture media. These sensor spots are mounted in transparent vessels made of plastics or glass for example. Plastic vessels with integrated pH sensors are ready-to-use as they are beta-irradiated and pre-calibrated. The pH is measured in a non-invasive and non-destructive manner from outside. They enable continous monitoring of pH without the need for at-line sampling.


  • Online monitoring without sampling
  • Non-invasive & non-destructive measurement
  • Pre-calibrated
  • Integrated in beta-irradiated disposables
  • Applicable for micro-liter scale to production scale
  • Optimized for culture media and physiological solutions

Selected Probes

Sensor Spots pH

Sensor Spots pH

Sensor Spots (SP) are the most versatile version of non-invasive pH sensors. They are attached to the inner surface of any transparent vessel.

Examples are

  • Shake flasks & spinners
  • Tubes & petri dishes
  • Cultivation bags

The transmitter with its optical fiber can be fixed opposite the sensor spot using our accessories (see our accessories brochure) which can be adapted for nearly all kinds of vessels.

Flow-Through Cell pH

Flow-Through Cell pH

The flow-through pH minisensor (FTC) is a miniaturized fiber chemical optical sensor integrated in a flow-through cell. It is connected to the transmitter by an optical fiber. The volume of liquid inside the FTC is about 250 microliters. The standard flow cell can be easily connected via Luer-Lock adapters to external tubing. The FTC is beta-irradiated and pre-calibrated.

Measurement Principle

Illustration: Measurement Principle pH

The Patented Dual Lifetime Referenced (DLR) Method

The patented DLR method enables internally referenced measurements. A combination of different fluorescent dyes detects intensity changes in the time domain. It is essential for the pre-calibrated measurements and the easy parallelisation of measurement through the identical calibration of large numbers of sensor spots.

Examples for Applications

Non-Invasive pH Sensor in Culture Bag
Pharma Industry: pH Monitoring in Bags

Bags and single-use bioreactors are in the process of revolutionising the way biopharmaceuticals are manufactured. Our non-invasive pH sensors are the tools to make the cultivation vessels fully disposable. As non-invasive DO sensors are also available, the two key parameters oxygen and pH can be controlled online.

pH Flow-Through Cells Integrated in Perfusion System
Online Measurement in Perfusion Systems

Beta-irradiated and pre-calibrated pH and DO flow-through sensors can be integrated into perfusion systems. This allows easy control of process parameters in perfusion reactors. Typically Luer connectors are used, though different sizes for larger or smaller flow rates are available.

Bioprocess Development: pH Monitoring in Shake Flasks

The pH is one of the major issues in the cultivation of cells, yeast or bacteria. Shake flask cultures are widely applied in academic and industrial bioprocess development. As adequate methods for real monitoring of pH were not available, cumbersome at-line sampling was used. The combination with non-invasive oxygen sensors in shake flasks provides new insights into metabolic activity and changes in metabolic pathways.

Cell Culture Dishes
Customized Micro Reactors and Ports

pH and DO sensor spots are mounted in customized micro reactors. They can be delivered beta-irradiated and pre-calibrated. Integration into a variety of polymeric surfaces is possible. Immobilisation on ports which are integrated into the reactors at the customer's facilities is a second application.

Technical Data

Please click to enlarge.

Transmitters & Accessories

pH-1 mini - Fiber Optic pH Meter

pH-1 mini

Fiber optic pH transmitter for use with non-invasive pH sensors.

pH-4 mini - Multi-Channel Fiber Optic pH Meter

pH-4 mini

4-channel fiber optic pH transmitter for use with non-invasive pH sensors.

pH-10 mini - Multi-Channel Fiber Optic pH Meter

pH-10 mini

10-channel fiber optic pH transmitter for use with non-invasive pH sensors.

Coaster CFG

Coaster CFG

The coaster CFG is used for shake flasks.

Stick-On Adapter SOA

Stick-On Adapter (SOA)

The Stick-On Adapter (SOA) is used for planar containers.

Adapter for Round Containers ARC

Adapter for Round Containers (ARC)

The ARC is used for round containers with diameters of 2.5 to 20 cm (1 to 8 inches).