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Continuous oil vapour measuring for your process safety

The METPOINT® OCV has been developed for measuring hydrocarbon vapours and gases in compressed air system applications. The detection levels are as low as one thousandth mg/m³ of residual oil vapour content and are executed continuously in ongoing operation. Shortened measuring intervals enable the rapid and reliable display of even the smallest deviations. This on-line monitoring process provides the certainty about the quality of your compressed air as an important element of your process safety at all times and at all quality-critical system points. The measurement data can be utilised for documenting the compressed air quality and for identifying contamination sources. The oil vapour measuring can be implemented with two various products: METPOINT® OCV and METPOINT® OCV compact. The similarities and differences will be explained in detail in this brochure.

METPOINT® OCV and METPOINT® OCV compact enable us to provide two products with which you can permanently measure the quality of your compressed air with regard to the oil vapour content.

Advantages of the METPOINT OCV | OCV compact

The details will be clarified more precisely on the following pages. Installation example with METPOINT

  • Safe
  • Reproducible accuracy of the measurement values by utilising reference gas generation (catalytic converter principle)
  • Automatic monitoring for the reference gas and sensor electronics
  • Issuing and transferring of alarm signal messages
  • Reliable
  • Pressure range from 3 to 16 bar
  • Online monitoring for the oil vapour concentrationData transfer to display as standard feature and control centre with customary communication methods
  • User-friendly
  • Visualisation of all measurement values
  • Flexible installation

There are however certain differences, which can qualify them more efficiently for the respective application purpose.


  • External test certificate: TÜV NORD, BfArM
  • Intuitive user interface and setting options


  • Robust industrial housing
  • Update of the measured value display every 4 sec.
Measuring and display unitSeparated, connected with data cable (maximum 5m)One unit with a robust industrial design
Protection classIP20 sensor unit
IP54 display unit
Updating the measuring value displayEvery 2 minutesEvery 4 seconds
Gas flow through rate2 - 3 Standard litre / minute, relating to 1.0 bar absolute and +20°C
bei 1 bar abs / 20°C
Approx. 1.20 Standard litre / minute relative to 1.0 bar absolute and+20°C
Interfaces4...20 mA, Ethernet4...20 mA, RS485/Modbus (only for measuring value)
Display and operating conceptMenu-guided on colour touch screen7-Segment display with 5 buttons forsetting configuration and alarm
Optical display for the operating statusColoured representation
on touch screen display
3 LEDs (each red/green) for purifier,PID and oil class
Measuring cell protectionUtilising error indicator
on display
The measuring cell will be protected against too high oil content via a valve switching process


Recognised procedure and external test certificate

The eligibility of the utilised measuring procedure in the METPOINT® OCV for the continuous recording of hydrocarbon vapour and gases in compressed air will be executed via comparison measurements in the PID procedure with reference procedures according to:

›› ISO 8573-5

›› Pharmacopeia (Ph. Eur. 2.1.6)

While the reference procedures according to ISO 8573-5 and the pharmacopoeia are based on a discontinued sampling method, the METPOINT® OCV measuring procedure provides the advantage of on-line monitoring. This therefore creates the prerequisite to immediately react to an increase in the residual oil content in the compressed air and possible breaching of the limiting values. The METPOINT® OCV is the first TÜV certified on-line system for recording the oil vapour content in compressed air. It has been certified by TÜV NORD according to the requirements ISO 8573-1.

Simple and safe operation

Both METPOINT® OCV systems provide output information about the current measurement value (oil vapour in mg/m³), the ISO 8573 oil class as well as the status of the measuring system and its components. In addition, the status of the measuring cell and the purifier will be displayed visually. You therefore have an overview about the measurement values, oil class, system status at all times and know immediately that your compressed air is correct.