Solar energy is a fast-improving Field, so ensuring photovoltaic (PV) panels performing at their best is not just ideal, it has become essential. Yet one common issue still goes overlooked: soiling. Dust, dirt, and airborne particles silently accumulate on panel surfaces, slowly cutting into energy production. For solar plant operators and cleaning companies alike, this can mean missed energy, and missed revenue.
To meet this challenge, SEVEN Sensor Solutions developed the 3S-SMS-P Portable Soiling Sensor, a purpose-built, patented tool that delivers on-site, accurate, and real-time soiling measurements. This solution was designed based on direct requests from PV cleaning companies, this solution empowers field teams to assess soiling levels before cleaning, support their work with data, and optimize when and where to take action.
A Tool Born from Real-World Needs
The 3S-SMS-P wasn’t created in a lab for theory; it was created in the field for practical impact. Cleaning companies needed a way to demonstrate their value to clients with actual data. They wanted to avoid the guesswork of deciding when to clean, and more importantly, prove when cleaning was or wasn’t needed.
They also needed a tool that could easily move across multiple sites, panels, and sections to run spot checks, plan work efficiently, or even carry out pre-audits for new projects. That’s why SEVEN designed this device to be portable, rugged, and intuitive, a real lift-and-shift solution that fits easily into existing workflows.
How It Works: Advanced Optics, Field-Ready Design
The 3S-SMS-P uses a high-lumen optical system to project light onto the panel’s surface. When light reflects or scatters back from dust particles, the sensor captures real data and calculates the soiling ratio. The Results appear instantly on the LCD touchscreen, ready for technicians to interpret and record.
What makes this system even more accurate is its adaptability. Users can input parameters like panel cell color, soil tone, and soil color; a feature that dramatically improves data quality across different sites.
Additionally, collecting data from three strategically selected points ensures precise and reliable soiling measurements.
A Critical Point to Consider:
The sensor should not be used on freshly cleaned panels.
Because when panels are spotless, there’s no soiling to analyze, and without real dust present, the color selection step becomes meaningless, leading to inaccurate results. You have always to measure before cleaning.
Built for the Field: Lightweight, Durable, and Reliable
| Component | Specifications |
| Output | RS485 (for logging systems and remote monitoring) |
| Operating Range | -10°C to +50°C, up to 90% RH |
| Battery | 12V 24Ah lithium, 5 hours of use per charge |
| Recharge Time | 3 hours |
| Sensor Unit | 4 kg (Ø280 mm x 180 mm) |
| Battery Box | 3.6 kg (220 mm x 232 mm x 137 mm) |
The design balances technical performance with practical usability, making it ideal for long days on large solar farms or remote sites.
Accuracy You Can Trust
- Soiling Ratio Range: 2% to 20%
- Resolution: 0.1%
- Measurement Uncertainty: ≤2%
Whether you’re a cleaning contractor or an O&M provider, these data provide confidence. No more assumptions or vague ‘Panels look dirty’ inspections. Accurate data tells you exactly when to clean, and, just as importantly, when not to.
Why this Sensor Matters for Cleaning and O&M Teams
For cleaning companies, this sensor is a game-changer.
- Prove their work value: Use pre-cleaning data to demonstrate to clients the impact of your cleaning service.
- Avoid unnecessary work: Only clean when it’s needed to save time, labour, and water.
- Plan smarter by checking different fields, modules or site sections to optimise cleaning schedules and priorities.
- Build trust: Provide clients with easy-to-understand reports, boosting retention and reputation.
- Use it as a pre-audit tool: It’s great for new client proposals or site analysis before contract negotiation.
Made in Türkiye, Trusted by the World
Crafted with precision in Türkiye, SEVEN’s portable soiling sensor is already being used by companies across continents. It is a dependable tool in any environment thanks to its compact form, smart interface and durable build.
Whether you’re managing a single rooftop or hundreds of megawatts in the field, the 3S-SMS-P helps you reduce cleaning costs, increase energy production, and bring hard data into the decision-making process.
Final Thought
In a market where efficiency is everything and trust is earned with data; the SEVEN Portable Soiling Sensor gives you the edge.