Solar PV module soiling sensor 3S-SMS-MB-M

for photovoltaic applicationsIEC 61724manual cleaning

Overview
The SEVEN Manual Soiling Sensor measures energy losses on photovoltaic panels by comparing a clean reference cell with a soiled reference cell. The reported soiling ratio corresponds directly to energy loss (e.g., 10% soiling = 10% energy loss). Data is transmitted via RS485 using Modbus RTU and the device is SunSpec compliant for integration with monitoring platforms.

How the Manual Soiling Sensor Works
The system uses two reference cells: one kept clean manually and one exposed to the same soiling conditions as the PV modules. By comparing irradiance between the cells, the sensor calculates the soiling ratio in real time and transmits it via Modbus RTU.

• One reference surface is cleaned manually by site personnel.
• The other reference surface is exposed to the same dust and dirt as the PV modules.
• Soiling ratio is calculated from irradiance differences and reported in real time.
• Communication: Modbus RTU over RS485; SunSpec compliant for plug-and-play integration.

Key Benefits

• Quantifies energy and revenue losses related to soiling for informed O&M decisions.
• Enables data-driven cleaning schedules to optimize costs and yield.
• Suitable for utility-scale plants, commercial rooftops and industrial installations.
• Rugged design: IP65 enclosure, UV-protected cable, wide operating temperature range.
• Calibrated under Class AAA solar simulator and validated with reference cells from ISFH and Fraunhofer ISE.

Why Soiling Monitoring Matters
Soiling reduces PV output and affects revenue. Typical impacts include:

• 2–5% annual loss in moderate climates.
• 10–15% or more in desert or high-dust regions.

Without monitoring, sites risk over-cleaning (wasted resources) or under-cleaning (lost yield). The sensor provides quantitative data to balance cleaning cost vs. performance gain.

Data & Communication
Output over a 3-wire RS485 bus using Modbus RTU. Supports up to 38400 Baud and an output rate of 1/s. SunSpec compliance ensures integration with SCADA, PLCs and third-party platforms.

Operation & Maintenance
Manual version requires operators to keep the clean reference cell free of dirt. Routine checks: clean reference cell, inspect cables/connectors, verify calibration annually to maintain IEC-compliant accuracy.

Compliance, Calibration & Testing
Compliant with IEC 61724-1 (Annex C). Each unit is calibrated under Class AAA solar simulator per IEC 60904-2 and IEC 60904-4 using an ISFH-calibrated reference cell and tested under natural sunlight with a Fraunhofer ISE-calibrated cell.

Frequently Asked Questions (selected)

• How does the Manual version differ from the Automatic? Same measurement principle and accuracy; the Manual version requires manual cleaning of the clean reference cell and is cost-effective for scheduled site visits.
• Is it reliable in extreme conditions? Yes—IP65 housing, UV-protected PUR cabling and operating range -40°C to +85°C.
• How often should the reference surface be cleaned? Clean the reference cell daily with a wet cloth; the soiled cell is cleaned periodically per site practice.
• Is it compatible with monitoring systems? Yes—Modbus RTU over RS485 and SunSpec compliance enable integration with most platforms.
• Delivery times & warranty Small orders: ~2–3 weeks; bulk (100 pcs): ~8–10 weeks. Warranty: 2 years against manufacturer defects.
• Price range Approx. 520 EUR – 950 EUR depending on options and accessories.

Technical Specifications

• Item Code: 3S-SMS-MB-M
• Soiling Ratio: 0% – 100%
• Resolution: 0.1%
• Uncertainty: ≤1%
• Irradiance: 0…1600 W/m²
• Followed Standard: IEC61724-1 (Annex C)
• Data Output: RS485 up to 38400 Baud
• Communication Protocol: Modbus RTU
• Output Rate: 1/s
• Operating Temperature Range: -40°C to +85°C
• Operating Humidity Range: 0 to 100%
• Power Supply: 12 to 30 V DC
• Power Consumption: 20 mA @ 24 V DC
• Electrical Connection: 3 m LIYYC11Y PUR cable, UV and weather resistant
• Galvanic Isolation: 1000 V between power supply and RS485 bus
• IP Rating: IP65
• Dimensions: 244 mm x 108 mm x 42 mm (W x L x H)
• Weight: 500 g
• Calibration: Calibrated under Class AAA solar simulator per IEC 60904-2 using an ISFH-calibrated reference cell
• Test: Tested under natural sunlight using a Fraunhofer ISE-calibrated reference cell