Class A pyranometer 3S-IS-T-I

current outputwith analog interface4-20 mA

Overview
The 3S-IS-T-I is a high-precision irradiance sensor designed for professional solar PV monitoring and performance testing. It measures solar irradiance (W/m²) using a monocrystalline silicon reference cell together with an internal PT1000 temperature sensor and a microcontroller that provides temperature-compensated irradiance values. Each unit is factory-calibrated, fully assembled, and supplied with a mounting bracket and a weather-resistant cable.

Key Features

• Analog 4-20 mA data output for easy integration with analog-compatible PLCs, SCADA systems, and dataloggers.
• Monocrystalline silicon reference cell (31 mm x 31 mm) to reflect real PV module behaviour.
• Internal PT1000 Class A temperature sensor for temperature compensation of irradiance readings.
• IEC 61724-1 Class A compliance with uncertainty ≤2% and Class A resolution/response characteristics.
• Robust aluminum housing with UV protection; IP54 standard with optional IP65 and IP68 ratings.
• Supplied with mounting bracket and 3 m UV and weather resistant LIYYC11Y PUR cable.

How it works
The sensor uses a monocrystalline silicon solar cell which generates a current proportional to incident solar irradiance. This current is processed through a precision shunt resistor and measured by onboard electronics. A PT1000 temperature sensor on the cell provides temperature data used by the microcontroller to calculate a temperature-compensated irradiance value. The processed values are output as an analog 4–20 mA signal. The electronics are designed for low power consumption to support continuous outdoor monitoring.

Why choose this sensor

• Trusted accuracy: IEC 61724-1 Class A compliance with uncertainty ≤2%.
• Fast response: typical response time 1 s (can be reduced to 0.5 s on request).
• Durable construction: UV-protected aluminum housing with optional higher IP ratings.
• Quick installation: plug-and-run design; supplied with mounting bracket and cable.
• Cost-effective for long-term outdoor monitoring with low drift.

Characteristics / Technical specifications

• Item Code: 3S-IS-T-I
• Reference Cell: Monocrystalline Silicon (31 mm x 31 mm)
• Current Shunt: High precision shunt resistor directly soldered to the terminals of the cell
• Irradiance Range: 0 – 1500 W/m²
• Uncertainty: ≤2%, as per IEC61724-1 standard Class A
• Resolution: 0.1 W/m² ≤ 1 W/m²; as per IEC61724-1 standard Class A
• Response Time: 1 sec. (less than 3 sec); as per IEC61724-1 standard Class A
• Drift: Very small drift of <0.3%/year
• Field of View: Larger than 160° as per IEC61724-1 standard Class A
• Tilt-Azimuthal Angle: 0°-0°, ≤ 1°; as per IEC61724-1 standard Class A
• Output Rate: 1/s
• Data Output: Analog 4-20 mA
• Power Supply: 12 to 30 V DC
• Power Consumption: 50 mA max @ 24 VDC
• Electrical Connection: 3 m LIYYC11Y PUR Cable, UV and weather resistant
• Cell Temperature Sensor Type: PT1000 Class A as per EN 60751
• Operating Temperature Range: -40°C to +85°C
• Operating Humidity Range: 0 to 100 %
• Box Dimensions: 140 mm x 110 mm x 42 mm (W x L x H)
• Weight: 0.3 kg
• IP Rating: IP54 (IP65, IP68 options)
• Sensor Housing Material: Aluminum
• Compliant Standard: IEC 61724-1:2021 and IEC 60904
• Calibration: Each sensor is calibrated under Class AAA Sun Simulator as per IEC 60904-2 and IEC 60904-4 using a reference cell calibrated by ISFH-Germany
• Test: Tested under natural sunlight using a calibrated reference cell from Fraunhofer ISE, Germany