Manual Soiling Sensor with HMI-PLC Monitoring – 3S-SMS-HMI-M

Technical Specifications of Manual Soiling Sensor With HMI-PLC Monitoring

What is the Purpose of a Soiling Sensor?

Solar panels accumulate dust over time. Dust and dirt on the panel surface block some of the sunlight, reducing production. This is called soiling loss. This loss is often invisible to the naked eye but is reflected in production reports.

The soiling sensor measures this loss numerically. It shows the soiling level in the facility and the resulting power loss. This allows you to decide when to clean the panels based on data, not guesswork. You avoid unnecessary cleaning costs and protect production by cleaning only when necessary.

How Does the Manual Soiling Sensor Work?

The system uses two reference cells. One sensor is periodically and manually cleaned and remains as a reference. The other is left exposed to contamination under the same conditions as the panels.

Both sensors measure solar radiation in W/m². The difference between the readings of the clean and dirty sensors indicates the level of dust accumulation on the panels. The system converts this difference into a soiling ratio according to the IEC 61724-1 Annex C standard. The result is displayed as a percentage on the HMI/PLC screen.

What Does an HMI/PLC Display Provide?

What distinguishes this model from a standard manual soiling sensor is its HMI/PLC touchscreen. You don’t need a separate data logger or monitoring system to read the soiling ratio. Everything is displayed on the screen.

• You can see the soiling ratio as a percentage directly on the screen.
• The system records data once every hour. You can view the historical data on the screen.
• You can transfer the recordings to a USB flash drive as a PDF or Excel file.
• Status LEDs indicate the health of the system. Green indicates that everything is working correctly, red indicates a lack of communication between the sensor box and the display, and yellow indicates that there is data that should not be considered according to the standard.

You simply supply power, do connector connections, and the system starts working.

The Difference Between Manual and Automatic Soiling Sensors

Unlike the automatic model, the manual soiling sensor does not include a water pump, water tank, and control unit. Cleaning of the reference sensor is done manually when the soiling level needs to be checked. This makes the manual system more economical than the automatic system. In facilities where a field team is present for regular cleaning, the manual system is a sufficient and cost-effective solution.

Key Advantages of Manual Soiling Sensor With HMI-PLC Monitoring

• No separate data logger is required: Thanks to the HMI/PLC display, the soiling level is shown directly on the device.
• Easy reporting: Data can be downloaded using a USB drive in the form of PDF or Excel file.
• Standard-based calculation: Soiling ratio is calculated according to IEC 61724-1 Annex C standard.
• An economical solution: It does not include a water pump or tank, making it more cost-effective than an automated system.
• Plug and play installation: The system comes pre-configured at the factory; you just need to power it on.
• Robust design: UV-resistant aluminium sensor housing and IP65 protection rating.
• SEVEN calibration: Irradiance sensors are calibrated under an AAA-rated solar simulator.

Installation and Use of Manual Soiling Sensor With HMI-PLC Monitoring

Installation is very simple.

• Mount the sensor box in a location where it will not be directly exposed to rain or sunlight. The sensor should be positioned in POA and parallel to the panels.
• Connect the soiling sensor to the HMI/PLC display using the provided connector.
• Connect the HMI/PLC display to a 24 V DC power supply.
• Clean the reference cell periodically as needed to monitor soiling ratio.