DOCA sensor deployment in an Australian automotive paint booth
A clean, stable air supply is essential in automotive paint finishing. Even trace oil contamination can create fisheyes, craters, poor adhesion, or uneven gloss, forcing operators to rework panels and interrupt production. These contaminants may enter compressed air as liquid oil, fine aerosol, or vapour, making conventional filter checks insufficient.
This case study follows a representative DOCA sensor deployment at an automotive components plant in Melbourne, Victoria. The site used compressed air for spray equipment, booth controls, robotic applicators, and maintenance tools. Its quality team wanted continuous evidence that the air reaching the paint booth remained suitable for high-value finishing work.
The DOCA project is developing an online optical sensor for detecting oil contamination in high-purity compressed air. Instead of relying solely on periodic sampling, the system provides an ongoing view of air quality and can support faster investigation when a compressor, dryer, filter, or distribution line begins to perform poorly.
The production problem
The plant operated several compressors feeding a ring main across fabrication and finishing areas. Air supplied to the paint booth passed through refrigerated drying, oil separation, coalescing filters, and point-of-use filtration. While this arrangement reduced contamination risk, it did not show precisely when oil breakthrough occurred.
Operators typically discovered a problem through paint defects, filter inspection, or laboratory analysis. That delay was expensive. A single contaminated batch could involve stripped parts, additional solvent use, lost booth capacity, and overtime for trades and quality staff. In Australia, where skilled maintenance availability can be tight during peak production periods, early warning has practical value.
Melbourne’s temperature swings and seasonal humidity also influenced the compressed-air system. The plant therefore needed monitoring that could operate reliably through winter condensation risks, summer heat, and changing production loads rather than a one-off test during ideal conditions.
Installing the optical monitoring point
The DOCA sensor was positioned on the clean-air line downstream of the final treatment stage and before the branch serving the paint booth. This location gave the team a realistic view of the air entering the finishing process while keeping the instrument accessible for inspection and calibration.
The installation included isolation valves, a bypass arrangement, condensate management, and a protected enclosure. The engineering team also reviewed electrical requirements and the booth’s hazardous-area classification. Where a sensor cannot be placed inside a classified zone, locating it outside the booth with a suitable sample connection can reduce installation complexity.
The commissioning team recorded the normal optical response during several production shifts. They correlated sensor data with compressor loading, filter differential pressure, dryer operation, and laboratory checks. This baseline helped distinguish normal variations from a genuine oil-contamination event.
Deployment checks used by the plant
- Confirm the sampling point represents air used by the paint process
- Verify flow, pressure, temperature, and condensate controls
- Check compatibility with Australian electrical and workplace safety requirements
- Record clean-air baseline readings across different production shifts
- Link alarms to maintenance and quality response procedures
Turning readings into plant decisions
The sensor’s value came from combining continuous measurement with existing plant information. A gradual change in the optical signal could indicate filter saturation or increasing compressor carryover. A sharp change might point to a failed separator, incorrect drain operation, or contamination introduced during maintenance.
The plant configured a staged response. A preliminary alert prompted inspection of filters and drains, while a higher alarm level triggered confirmation sampling and a review of affected production. This avoided treating every small fluctuation as an emergency and gave technicians a clear path from data to action.
For Australian operators, the approach also supports practical documentation under state and territory work health and safety duties. A Melbourne facility may work within Victoria’s Occupational Health and Safety framework, while a comparable site in Sydney would apply New South Wales requirements. The sensor does not replace risk assessment or compliance testing, but it strengthens evidence that critical air services are being controlled.
Information captured during the trial
- Oil-contamination trend and alarm history
- Compressor duty, dryer status, and filter differential pressure
- Paint defects linked to production time and booth zone
- Laboratory comparison results for liquid, aerosol, or vapour contamination
- Corrective actions, downtime, and material saved through early detection
Effects on paint quality and maintenance
During the trial, the maintenance team used the online signal to identify changes before they became widespread finish defects. Inspection could be directed towards the relevant compressor train or filtration stage instead of checking the entire plant. This shortened fault-finding time and reduced unnecessary replacement of serviceable filters.
Quality staff also gained a stronger basis for releasing production after maintenance. Rather than relying only on a visual check of the booth or a delayed sample result, they could review the air-quality trend and confirm that readings had returned to the established baseline.
The financial case was especially relevant to the local market. Australian automotive manufacturing includes vehicle components, specialist vehicles, aftermarket products, and export-oriented finishing operations. In these settings, avoiding a small number of rejected parts can justify monitoring investment when paint, labour, booth capacity, and freight costs are considered in Australian dollars.
Lessons for Australian industrial sites
The deployment showed that sensor location and operating procedure matter as much as the instrument itself. A reading taken too close to a compressor may not represent booth air, while a poorly managed sample line can introduce condensation or distort the result. Installation should therefore involve compressed-air, automation, electrical, and paint-quality specialists.
The project also highlighted the need to define ownership. Maintenance responds to equipment alarms, production protects the schedule, and quality decides whether affected parts require containment. A shared dashboard and written escalation process prevented the sensor from becoming another isolated data source.
For plants in Brisbane, Sydney, Adelaide, or Melbourne, local conditions and regulatory expectations will differ. However, the core principle remains consistent: continuous oil monitoring can support cleaner compressed air, earlier intervention, and more defensible process control in demanding finishing environments.
From pilot data to wider deployment
After the paint booth trial, the plant considered extending monitoring to critical branches supplying robotic spray equipment and clean preparation areas. Comparing several points could reveal whether contamination originated at the compressor room, the main ring, or a local point-of-use assembly.
The results also provided useful feedback for the DOCA project’s research and development work. Field data from an industrial environment can help refine optical detection of oil in liquid, aerosol, and vapour forms, while supporting validation, industrial application planning, and future patent development.
For manufacturers, the strongest deployment model is progressive. Begin with the process where contamination has the highest cost, establish a dependable baseline, and then expand monitoring when the response workflow is proven.
Contact the DOCA Project to follow the sensor’s technical progress and explore how online oil-contamination detection could support compressed-air quality, paint performance, and maintenance control in your facility.