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Fixed Needle-Type Oxygen Sensors

  • Optical oxygen minisensors
  • Original REDFLASH-technology
  • Works in gas (%O2) and in liquids (DO)
  • No oxygen consumption
  • Response times down to <1 s
  • Fixed sensor tip surrounded by needle
  • Stainless steel
  • >3 years shelf time
  • Trace oxygen versions available

The sensor tip of these fiber-optic oxygen mini- and microsensors is glued into a stainless needle. The complete sensor is resistant to corrosive environments (e.g. seawater), because all metallic parts are made of stainless steel. The following sensor types are available:


OXF500PT and OXF900PT: The very sensor tip is positioned exactly within the bevel of a bevelled 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, aluminium packages). The needle is filled with glue ensuring no air leakage through the needle when puncturing packaging material. The OXF500PT is recommended for measurements in the gas phase and for insertion through thin septa or packaging material. The OXF900PT has a thicker needle applicable for thicker septa or packaging material. Application in liquids is also possible, but requires special precautions in order to remove "trapped" gas bubbles at the sensor tip.

OXF1100: The fragile sensor tip extends ca. 2mm from a straight-cut needle. The OXF1100 can be applied in liquids and in gases. The complete inner space of the syringe needle is carefully filled with glue, minimizing any gas reservoir which might slow down the repsonse time of the sensor.

Trace range versions. Special trace range versions are available for high precision measurements close to 0%O2. They offer about 5x higher resolution compared to the full range oxygen sensors. The recommended measuring range is 0-10% O2. However, a calibration at ambient air (21% O2) is possible, ensuring a straightforward calibration without the need of special calibration standards.



Compatible oxygen meters

FireStingO2 (FSO2-x)
FireStingGO2 (FSGO2)
FireStingO2-Mini (FSO2-MINI-ST)
FireStingO2-SubPort (FSO2-SUBPORT) for sensors with underwater connectors (option -SUB)

Full Range Versions

Item No. Description
(Needle / Tip Diameter)
Time (s)**
in EU*
OXF500PT Fixed Oxygen Minisensor
Protected Tip (0.5mm / 230µm)
<2 s (gas) 290 €
OXF900PT Fixed Oxygen Minisensor
Protected Tip (0.9mm / 230µm)
<2 s (gas) 290 €
OXF1100 Fixed Oxygen Minisensor
(1.1mm / 430µm)
<5s (liquid)
<3s (gas)
290 €
OXF500PT-OI Fixed Oxygen Minisensor
Protected Tip, Optical Isolation (0.5mm / 230µm)
<4s (gas) 350 €
OXF900PT-OI Fixed Oxygen Minisensor
Protected Tip, Optical Isolation (0.9mm / 230µm)
<4s (gas) 350 €
OXF1100-OI Fixed Oxygen Minisensor
Optical Isolation (1.1mm / 430µm)
<10 s (liquid)
<6 s (gas)
350 €

Trace Range Versions

Item No. Description
(Needle / Tip Diameter)
Time (s)**
in EU*
TROXF1100 Fixed Trace Oxygen Minisensor
(1.1mm / 430µm)
<15 s (liquid)
<2 s (gas)
290 €

* Only EU-Prices shown. Contact us for pricing outside EU. Not for resale.

** Typical response times for 90% signal change (T90).
     For liquids: measured for the transition from air into a stirred solution of 1% Na2SO3.


Item No. Extension Description Extra Charge
-CL4 Cable length of ca. 4m (instead of standard 2m cable length) add 30 €
-OI Black optical isolation on the very sensor tip. Recommended for applications with intense background illumination (e.g. direct sun light) or for media with strong luminescent properties (e.g. algae cultures). Refer to the tables above for available sensor versions. see above
-HS High speed. Selected sensors with fast response times. on request
-UHS Ultra high speed. Selected sensors with very fast response times. on request
-SUB Underwater connector (instead of standard ST-connector) needed for applications with the underwater OEM-solution FireStingO2-SubPort. Contact us for available sensor versions. no extra charge
-CLx Custom cable length of x meter (max. 20m) on request
-Nx/y Custom needle types (x mm in diameter, y mm in length) surrounding the sensor tip. Contact us for possible combinations. on request

: Item no. OXF1100-CL4 designates a minisensor with 4m cable.

Tip Geometries

True to scale drawings with syringe needle (grey), optical fiber (pink), and oxygen sensitive REDFLASH dye (green)


Given for 2-point calibrated oxygen sensors at 20°C and 1013mbar absolute pressure.

Full range versions hPa %O2 %air sat. mg/L
Optimum measuring range 0-500 0-50 0-250 0-23
Maximum measuring range (not specified) 0-1000 0-100 0-500 0-45
Detection limit 0.2 0.02 0.1 0.01
Resolution at 1% O2 0.1 0.01 0.05 0.005
Resolution at 20% O2 0.5 0.05 0.25 0.025
Accuracy at 1% O2 ±0.2 ±0.02 ±0.1 ±0.01
Accuracy at 20% O2 ±2 ±0.2 ±1 ±0.1
Trace range versions hPa %O2 %air sat. mg/L
Optimum measuring range 0-100 0-10 0-50 0-5
Maximum measuring range (not specified) 0-210 0-21 0-100 0-9
Detection limit 0.05 0.005 0.02 0.002
Resolution at 0.2% O2 0.02 0.002 0.01 0.001
Accuracy at 0.2% O2 typ. 2% of reading, but not better than 0.01%O2
All versions
Temperature range 0 to 50°C (specified), -20 to 70°C (not specified)
Minimum lifetime 1,000,000 data points
Application areas Laboratory, industry, research. Not for medical or any other safety-critical applications. Not for application in humans or in food intended for human consumption.
Compatibility Gas-phase, aqueous solutions, ethanol, methanol, isopropanol (note: the optional optical isolation (-OI) is not compatible to ethanol, methanol, isopropanol)
Cross sensitivity Other organic solvents, chlorine
No cross sensitivity pH 1-14, CH4, CO2, H2S, any ionic species
Sterilization Ethylene oxide (EtO), 70% ethanol, 70% isopropanol
Cleaning 3 % H2O2, ethanol, soap solution
Storage time >3 years in darkness at room temperature
Calibration Single point, two point calibration
Dimensions Total length ca. 170 mm (from needle tip to cable), shaft diameter 8 mm
Needle length 40 mm
Tip positions Fixed
Connector ST-plug (optional: underwater connector)
Cable length 2m or 4m (standard), optional up to 20m