SP-PSt7 optical O2 Sensor Spot

Small Optical Sensor for Contactless Oxygen Measurements

Oxygen Sensor Spot SP-PSt7-NAU

The oxygen sensor spot SP-PSt7-NAU can be integrated in any transparent or semi-transparent vessel, or optical window while measurements are then taken contactless from the outside – through the vessel wall. Due to their small size these sensors are most versatile and can be implemented in manifold applications for measuring dissolved and gaseous O2. These oxygen sensor spots have a measurement range from 0 – 100 % O2, with a detection limit of 0.03 % O2. The SP-PSt7-NAU does not stand autoclaving.

  • Non-invasive measurements through the vessel wall
  • No consumption of oxygen
  • Signal independent of flow velocity
  • Measures oxygen in liquids as well as in gas phase
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Bioprocess Development: Oxygen Monitoring in Shake Flasks

O2 supply is one of the major issues in the cultivation of aerobic organisms. Shake flask cultures are widely applied in academic and industrial bioprocess development. As adequate methods for real monitoring of dissolved oxygen were missing, sufficient O2 supply is usually assumed. The non-invasive oxygen sensors in shake flasks now ensure oxygen supply and give new insights into metabolic activity.

Respiration & Photosynthesis: Oxygen Monitoring in Glass Vials

Determination of respiratory activity is often performed for water organisms such as invertebrates, larval stages or eggs, but also for bacteria, cell cultures, yeasts or fungi. For algae measurement of photosynthetic activity is of great interest. Using our 20 mL SensorVial with an integrated sensor stripe oxygen can be measured simultaneously in the liquid sample and in the headspace. Autoclavable SensorVials for stirred and non-stirred applications are available.


SpecificationsGaseous & Dissolved O2Dissolved O2
*after two-point calibration as described in the manual
Measurement range0 – 100 % O2
0 – 1000 hPa

0 – 45 mg/L

0 – 1400 µmol/L
Limit of detection0.03 % oxygen15 ppb

± 0.01 % O2 at 1  % O2
± 0.05 % O2 at 20.9 % O2

± 0.005 mg/L at  0.4mg/L

± 0.025 mg/L at 9.06 mg/L
Accuracy at + 20 °C*± 0.05 % O2 or ± 3 % rel.
Measurement temperature rangefrom 0 to + 50 °C
Response time (t90)< 6 sec.< 40 sec.
CompatibilityAqueous solutions, ethanol, methanol
No cross-sensitivity

pH 1 – 14
CO2, H2S, SO2
Ionic species


Organic solvents, such as acetone, toluene, chloroform or methylene chloride
Chlorine gas

Sterilization procedureEthylene oxide (EtO)
Gamma irradiation
Cleaning procedure

3 % H2O2
Aqueous solutions

CalibrationTwo-point calibration with oxygen-free environment (nitrogen, sodium sulfite) and air-saturated environment
Storage stability60 months provided the sensor material is stored in the dark at room temperature

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Do I have to mount the sensors in the dark because it says "Protect from light" on the packing? Do the sensors work in turbid solutions? Does each oxygen sensor spot need a separate calibration, or are the calibration values valid for the complete sensor spot batch? How can I convert an oxygen value into a different oxygen unit? How can I prepare the calibration solutions cal0 and cal100 for oxygen sensors? How do I import data into excel from a text file containing measurement data? How do I verify whether the oxygen sensor is giving correct readings (performance proof)? How does an oxygen sensor work? How does salinity affect the oxygen measurement? How does temperature affect the oxygen measurement? In which vessel can I integrate a sensor spot? Is the glue or the sensor spot biocompatible - which tests were done? Are there any studies on leachables and extractables? Is there a standard recommended distance to place the polymer optical fiber (POF) from the sensor spot? The Stern-Volmer-equation What does -YAU, -NAU or -SA stand for in the oxygen sensor spot names and what is the difference between those sensor types? What factors will affect the oxygen reading? What is the time of delivery? Where do I need sensor spot sizes different from the common diameter of 5 mm (approx. 0.2 inch)? Which glue can I use to integrate optical sensor spots? Which side of the oxygen sensor spot should face the medium? Which substances can interfere with the optical O2, pH and CO2 measurements?


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