Continuous oil vapour measuring for your process safety

Oil contamination can affect compressed air processing systems in many different ways, posing a danger to the safety of workers, the environment and the production equipment. Monitoring systems such as the METPOINT OCV compact continuously control the compressed air accurately and according to applicable standards for the residual oil vapour concentration . You therefore retain the compressed air quality.


Function of oil vapour measuring

In the METPOINT OCV system, a PID sensor works according to the principle of photo-ionization using a UV lamp. To increase the precision and to compensate for the smallest fluctuations, the determined values ​​are temperature and pressure compensated. This fulfills the requirements of ISO 8573. As a continuous self-control of the measuring system, a reference gas generated by means of an integrated catalytic converter is used. In the periodic change between measuring air and reference air, the function of the PID measuring cell is continuously controlled and adjusted.

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Advantages of the METPOINT® OCV system

  • Reproducible accuracy of the measurement values by utilising reference gas generation
  • Automatic monitoring for the reference gas and sensor electronics
  • Issuing and transferring of alarm signal messages

  • Pressure range from 3 … 16 bar
  • Online-monitoring for the oil vapour concentration
  • Data transfer to display as standard feature and control centre with customary communication methods

  • Unambiguous visualisation of all measurement values
  • Flexible installation
  • Robust industrial housing

Permanent and precise monitoring of oil vapour

The METPOINT OCV compact 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.

Technical data for METPOINT® OCV compact

Medium Compressed air free of aggressive, corrosive, caustic, toxic, flammable and combustion supporting materials or substances.
The use of a compressed air preparation adapted to the measurement task is necessary.
Measured value Residual oil content in mg of oil/normal m³, relative to 1.0 bar, +20°C, 0% relative humidity, according to ISO 8573-1
Detectable substances Polyalphaolefines, aromatics, hydrocarbons, aliphatic hydrocarbons and functional hydrocarbons
Detection limit (residual oil) 0,001 mg/m³
Measuring gas humidity ≤ 40 % relative humidity, PDP maximum +10°C non-condensing humidity
Storage temperature +5°C ... +50°C
Excess operating pressure 3 … 16 bar(a), optional pressure reducer pre-switched for up to 300 bar (a)

Measuring and display unit one unit with a robust industrial design
IP class IP54 / DIN EN 60529
Measuring range: <0,01 - 2,500 mg/m³
Updating the measuring value display every 4 seconds
4...-20 mA, RS485/Modbus (only for measuring value)
7-Segment display with 5 buttons for setting configuration and alarm
Optical display for the operating statuses:
LEDs (each red/green) for purifier, PID and oil class
Measuring cell protected against excessive oil content with a valve switch

Recognised method and external test certificate

The eligibility of the utilised measuring methods 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 process 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 an interrupted sampling method, the METPOINT OCV measuring methods provide 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. METPOINT OCV is the first TÜV certified* on-line system for the recording the oil vapour content in compressed air. It has been certified by TÜV NORD according to the requirements of ISO 8573-1.

Simple and safe operation

The METPOINT OCV compact provides 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 reference gas generation (purificator) will be displayed visually. You therefore always have an overview about the measurement values, oil class, system status at all times and know immediately that your compressed air is correct.  

Our calibration service for your METPOINT® OCV

Transducers and transmitters are exposed to mechanical stress and temperature fluctuations among others. As a result e.g. the measuring accuracy of sensors decreases and generates a so-called “drift”, which then falsifies the measured results and can thereby impair production and product quality. BEKO TECHNOLOGIES provides a comprehensive range of calibration services for volume flow sensors, pressure dew point transmitters, pressure measurement converters and analyses devices. The calibration is executed according to a specified calibration method from BEKO TECHNOLOGIES and is a so-called ISO calibration. ISO calibration is based on reference measurements performed with externally provided test specimens and certified reference devices. All reference devices can be traced back to national standards. The relevant procedures and methods meet the requirements of the DIN EN ISO 9001 quality standard.

Contact Service


Product Range
4 MB
Competence in Measurement
2 MB

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application report
Application Report METPOINT OCV

Industry: Applied medical research
Customer/Location: Laser research centre CALA / Munich (Germany)
Use of compressed air: Measuring, control, process air


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