Class A albedometer 3S-ALBEDO

for photovoltaic systemsfor photovoltaic systems

Overview
The 3S-ALBEDO is a PV albedometer for bifacial systems that measures plane-of-array (POA) and reflected irradiance and computes solar albedo (reflected/incident). It includes an internal reference cell temperature sensor, is supplied with a mounting bracket and a 3 m UV‑resistant PUR cable, and outputs data via RS485 using Modbus RTU.

Key capabilities

• Measures POA irradiance and reflected irradiance for albedo calculation
• Computes solar albedo (ratio reflected/incident)
• Internal PT1000 temperature compensation; optional external PT1000 module sensors on 3S-ALBEDO-2T
• RS485 Modbus RTU output for integration with dataloggers, PLCs and SCADA
• Delivered with mounting bracket and pre-wired cable for quick installation

How it works

• Monocrystalline silicon reference cell (31 × 31 mm) generates current proportional to irradiance
• Precision shunt converts current to measurable signal
• Onboard PT1000 corrects temperature-dependent deviations
• Electronics calculate temperature-compensated irradiance values in W/m² and derive albedo
• Data transmitted via RS485 (Modbus RTU) up to 38400 Baud

Why choose 3S-ALBEDO

• Compliance with IEC 61724-1 Class A; measurement uncertainty ≤1%
• Fast response: 1 s standard (configurable to 0.5 s on request)
• Outdoor-ready: UV-protected aluminium housing and UV-resistant PUR cable; IP54 standard (IP65/IP68 optional)
• Galvanic isolation between power and RS485 (1000 V)
• Expandable: 3S-ALBEDO-2T supports 2× external PT1000 module sensors

Available models

• 3S-ALBEDO — standard PV albedometer with RS485 Modbus RTU (no external module sensors)
• 3S-ALBEDO-2T — adds support for 2× external PT1000 module temperature sensors

Specifications

• Sensor type: Silicon reference cell (31 × 31 mm)
• Measured data: POA irradiance; reflected irradiance; solar albedo; cell temperature (and 2× module PT1000 on 3S-ALBEDO-2T)
• Irradiance range: 0–1600 W/m²
• Albedo range: GH 0–1 (POA > 0)
• Uncertainty: ≤1% (IEC 61724-1 Class A)
• Resolution: 0.1 W/m²
• Response time: 1 s (configurable to 0.5 s)
• Field of view: 170°
• Output rate: 1 / s; Data output: RS485 up to 38400 Baud; Protocol: Modbus RTU
• Power supply: 12–30 V DC; Consumption: ≈20–22 mA @ 24 V DC
• Cable: 3 m PUR, UV and weather resistant
• Galvanic isolation: 1000 V between power and RS485
• Module sensor type: PT1000 Class A (EN 60751:2022)
• Operating temperature: -40°C … +85°C
• Dimensions: 138 × 112 × 39 mm (L × W × H); Weight: ≈0.52–0.53 kg
• IP rating: IP54 standard (options IP65, IP68)
• Standards & calibration: IEC 61724-1:2021; IEC 60904 series; calibrated on Class AAA sun simulator, reference cell traceable to ISFH
• Recommended recalibration interval: 2 years; Warranty: 2 years; Origin: TÜRKİYE