Ultra-Trace Oxygen Sensor Cap for Underwater Meters


  • Sensor screw cap with integrated optical ultra-trace oxygen sensor
  • Fast sensor with low drift
  • For all devices with -SUB connector
  • Minimized maintenance by simply exchanging the cap

The ultra-trace oxygen sensor cap UTROXCAP-SUB integrates an ultra-trace range oxygen sensor spot (without optical isolation), especially developed for underwater and deep-sea applications. The UTROXCAP can be screwed directly onto the PyroScience SUB-connector of a compatible underwater read-out device. The UTROXCAP-SUB is protected and hence highly robust against mechanical impact and ideal for long-term monitoring applications. The sensing principle is based on an optical detection method and shows virtually no drift and fast response. The UTROXCAP-SUB is especially suited for trace oxygen detection in oxygen minimum zones or during de-oxygenation events underwater.


Ultra-Trace Range. The Ultra-Trace Oxygen Sensor Cap is available for high precision deep sea measurements close to 0% oxygen. They offer about 10x higher resolution compared to standard range oxygen sensors. The specified measuring range is 0 - 44 µg/L (ppb).

Easy calibration. The sensor comes pre-calibrated and can be easily calibrated at 0% oxygen with our calibration capsule 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.

SUB-connector (-SUB). Underwater sensor connector (instead of standard ST-connector) needed for applications with underwater devices.


Price List

0% O2 Calibration Capsules 


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

Underwater Sensor Protection Cap


  • Compatible with all sensor caps with SUB-connector
  • For APHOX®-L and APHOX®-T shallow water devices
  • Protection of sensor caps against biofouling
  • Easily replaceable

Every PyroScience oxygen meter with a SUB-connector (underwater devices) is compatible to 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


This combination enables: 

  • Robust ultra trace range oxygen measurements in deep sea
  • Autonomous logging with the AquapHOx-LX Logger

Exemplary Setup


This combination enables: 

  • Robust ultra trace range oxygen measurements in deep sea
  • Very low power consumption
  • UART interface

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