Measurement Equipments

Compressed Air Quality Measurement

Show exactly how clean your air is, in the ISO 8573-1 purity classes your specifications are written in.

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A portable air quality measurement kit in an open case, with particle, oil vapour and dew point instruments and a sample connection

Product overview

Proof of purity, not a promise

Our air quality measurement equipment measures the contaminants that ISO 8573-1:2010 uses to define air purity: solid particles, water and total oil. Each result is reported against the purity class designation, so the air reaching your process can be checked against the class written into its specification.

A laser particle counter counts particles from 0.1 µm in the standard size bands, a photo-ionisation detector measures oil vapour down to thousandths of a milligram per cubic metre, and a dew point sensor at line pressure measures water. Every result is converted to the reference conditions of 20 °C, 1 bar absolute and 0 % relative humidity.

Use it for spot audits at commissioning, validation or troubleshooting, or as permanent monitoring that raises an alarm when a limit is exceeded. Either way you get a dated, traceable record, and a true picture of what your dryers and filters deliver under real site conditions.

An air quality measurement station on a wheeled aluminium frame, with its display and sampling connections
  • 0.1 µmSmallest particles counted
  • 0.001 mg/m³Trace oil vapour measured
  • ISO 8573-1Results stated in its purity classes
  • 20 °C · 1 barAbsolute, at 0 % RH: the reference conditions

Benefits

What your air really contains

Particles below 1 µm, oil vapour and water vapour are all invisible. Here is what that hides, and what measurement shows you.

  • Contamination made visible

    The problem

    Air at Class 1 for oil holds at most 0.01 mg/m³, and the factor of 100 between Class 1 and Class 3 oil has no visible sign.

    How it solves it

    Particles are counted from 0.1 µm upward, and oil vapour is detected in the thousandths of a milligram per cubic metre.

  • Ratings checked on site

    The problem

    A saturated, bypassed or badly sealed coalescing filter lets contamination pass while its differential pressure gauge still reads normal.

    How it solves it

    New dryers and filters are accepted on measured results at commissioning, under your real site conditions.

  • Faults traced to source

    The problem

    Contamination often shows up in the product before anyone suspects the air.

    How it solves it

    Measurements at successive points identify the failing compressor, dryer, filter or pipe section, and take the guesswork out of troubleshooting.

  • Early warning

    The problem

    Desiccant ageing and a carbon stage nearing exhaustion creep up slowly.

    How it solves it

    Continuous monitoring flags a rising dew point or oil level while your air is still inside its class limits.

  • Maintenance by condition

    The problem

    Filter elements, carbon and desiccant changed on a fixed schedule are either left too long or changed too soon.

    How it solves it

    Replace them when measured performance calls for it, not only by the calendar.

  • Audit-ready evidence

    The problem

    A purity class that has never been measured cannot be shown to an auditor.

    How it solves it

    Time-stamped, calibrated results in ISO 8573-1 classes serve GMP, HACCP, HTM 02-01 and EN 12021 audits.

Where it’s used

Wherever air touches product, process or people

The purity class in a specification applies where the air meets its use, and that is where we measure it.

  • Wine bottles moving along a bottling line

    Food and beverage

    BCAS Guideline 102 specifies Class 2:2:1 for direct contact with food and Class 2:4:2 for indirect, with records supporting HACCP.

  • Yellow tablets spilling from a medicine bottle

    Pharmaceuticals

    Air for tablet coating, granulation, fermentation and filling, qualified during validation and monitored routinely under GMP.

  • Robots welding a car body on an assembly line

    Automotive paint shops

    Particles, oil and moisture are checked because they cause craters, fisheyes and adhesion failures.

  • A hand mixing paint in open tins of colour

    Surface finishing

    Oil vapour and particles cause coating and paint defects that appear only after finishing.

  • Blue plastic bottle caps in a moulded tray

    Packaging and PET blow moulding

    The air that inflates a bottle touches the inside surface of the container.

  • Test tubes of coloured chemicals in a laboratory rack

    Oil, gas, power and process plants

    Instrument air is checked against the dew point and particle requirements of ISA-7.0.01.

Also hospitals and medical gas systems to the European Pharmacopoeia and HTM 02-01, breathing air to EN 12021, clean dry air in electronics and semiconductors, laboratory air for analysers and nitrogen generators, and verification of dryers and filters at commissioning.

How it works

Sample, measure, classify

A sample drawn from the centre of your pipe is split between instruments, one for each contaminant, and the results are combined into one purity class.

How compressed air quality is measured: a probe at the pipe centreline draws a sample that is split between a laser particle counter, which sorts particles by the light each one scatters, an oil vapour photo-ionisation detector with catalytic zero air, and a dew point sensor at line pressure. A logger converts the results to ISO 8573-1 reference conditions and states the purity class as particles, water and oil. 0.1–0.50.5–11–5 ISO 8573-1:2010Class 1:2:1particles : water : oil20 °C · 1 bar absolute · 0 % RH Treated air inTo point of use Sampling probeIsolation valve DiffuserParticle counter CatalyticconverterSwitching valveOil vapourdetector Dew pointsensor 12345Treated compressed airMeasurement signalLaser beamUltraviolet lightVented to atmosphere

  1. 1. Draw a true sampleA probe at the pipe centreline faces into the flow, with gas entering it at the stream’s own velocity, so particles and droplets are collected in their true proportion.

  2. 2. Count the particlesA diffuser brings the sample to atmospheric pressure and a pump draws a fixed flow through the optical cell. Each particle crossing the laser beam scatters a pulse of light, and its height sorts the particle into the 0.1–0.5 µm, 0.5–1 µm or 1–5 µm band.

  3. 3. Measure the oil vapourA 10.6 eV ultraviolet lamp ionises hydrocarbon molecules but not the main constituents of air, and the ion current gives their concentration. A switching valve alternates the sample with zero-reference air from a catalytic converter, cancelling drift and humidity effects.

  4. 4. Measure the dew pointA sensor in a small chamber at line pressure reads the pressure dew point directly, while a needle valve bleeds a small, continuous flow to keep the sample fresh.

  5. 5. Assign the classEvery result is converted to 20 °C, 1 bar absolute and 0 % relative humidity and written as particles : water : oil, such as 1:2:1. The weakest contaminant decides whether your specification is met.

Results are stated at the ISO 8573-1 reference conditions: 20 °C, 1 bar absolute and 0 % relative humidity.

Get the full details

Our brochure covers it in detail, and our questionnaire tells us what we need to recommend the right one for your plant.

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