Protected Tip Oxygen Minisensor


  • Sensor tip protect by needle
  • Needle diameter 500µm
  • Optimized for measurements in gas
  • Optically isolated (OI)
  • 4m cable length (CL4)

The fiber-optic oxygen sensors from PyroScience feature no oxygen consumption, no stirring sensitivity, an extremely long shelf time, resistance to corrosive environments (e.g. seawater) and are suitable for multiple applications in gas, water and aqueous samples.

This fiber-optic minisensor consist of an optical fiber with a sensor tip diameter of 430 µm. Compared to a microsensor, this sensor is suited for slightly larger samples, long-term measurements and profiling applications with less spatial resolution requirements.

Typical application:

  • For measurements in illuminated or fluorescing gas samples

Standard range. This sensor is specified for an optimum measuring range of 0 to 500 hPa oxygen (0 -250% air saturation). However, without specifications, it is possible to measure in up to 1 bar pure oxygen/100% oxygen saturation/100% oxygen. For detailed specifications, see the respective pdf file in the Downloads tab.

Protected tip. The very sensor tip is positioned exactly within the bevel of a beveled needle tip giving mechanical protection. This type is especially designed for performing oxygen measurements in gas samples after sensor insertion through rubber septa or packaging material (paper, plastics, aluminum packages). The needle is filled with glue ensuring no air leakage through the needle when puncturing packaging material. Application in liquids is possible, but requires special precautions in order to remove "trapped" gas bubbles at the sensor tip.

Optical isolation. For applications at high ambient light (e.g. direct sunlight, illuminated samples) and in fluorescing / light-sensitive samples, an additional optical isolation (-OI) protection layer is added to the sensor surface to reduce enhanced sensor aging and to avoid interference with the oxygen measurements

4m cable length (-CL4). Cable length of ca. 4m, instead of standard 2m cable length.

Specialized for gas. This sensor is specifically designed for measurements in gases. The cannula is filled with glue, to prohibit any gas transfer and any pollution of the sample through unwanted gas transfer through the cannula.


ST-connector. This connector is our standard sensor connector for PC-operated and handheld FireSting devices.

Easy calibration. A simple ambient air calibration can be performed with a few clicks (<1 minute for equilibrated setup). For precise oxygen measurements close to 0% we also offer easy-to-use calibration capsules (OXCAL). Simply dissolve the content of one calibration capsule in 100 ml distilled water, wait 10-15 minutes, perform the 0% calibration and start measurements with a calibrated sensor. For detailed calibration recommendations refer to the manual in the downloads tab.

Applications. To get an overview of potential applications and to see our sensors in action, please visit our Applications site!

Sensor Versions. There are further versions available of this sensor type.  Please use the filter function or the inquiry form to find the suited sensor version for your application.

Price List

0% O2 Calibration Capsules 


For recommended 0% O2 calibration of optical oxygen sensors. Each capsule results in 50mL calibration solution (PU=10).

Every PyroScience oxygen meter with ST-connector is compatible with this sensor. Use this link to get a list of all compatible meters. Select additional requirements to find the optimal meter for you and your application!


Exemplary Setup


Choose the one channel oxygen meter FireSting-O2 with the protected tip oxygen minisensor OXF500PT-OI-CL4.

  • Good value
  • Ready to go lab setup

Exemplary Setup


Choose the pocket oxygen meter FireSting-GO2 with the protected tip oxygen minisensor OXF500PT-OI-CL4.

  • Stand alone logging
  • With battery and display

Exemplary Setup


Choose the multi-analyte FireSting-PRO (4 chan.) with the protected tip oxygen minisensor OXF500PT-OI-CL4.

  • 4 freely configurable optical channels
  • + Additional pH sensor support

Would you like to stay informed?