Introducing the SEVEN Class A Thermopile Pyranometer

by Robert Schreiber
Berlin, Germany (SPX) Dec 19, 2025

SEVEN introduces the newly developed Class A Thermopile Pyranometer - a cutting-edge solution designed for high-precision solar radiation monitoring in PV plants, meteorological stations, and research applications.

SEVEN Sensor Solutions: A Global Leader in Sensor Technology

SEVEN Sensor Solutions is a leading manufacturer of high-quality sensors mainly designed to monitor the performance of PV Plants (Photovoltaic Plant). As a company specialized in sensor manufacturing, SEVEN has successfully expanded into other fields, including meteorological and silo-related applications.

Thanks to its wide range of sensors, SEVEN Sensor has successfully reached more than 85 countries worldwide, from Japan to the USA, and from Sweden to South Africa.

Driven by a strong focus on R&D, SEVEN has been granted two patents for its innovative sensor technologies.

SEVEN is well known in the market for its high-quality Reference Cells and Soiling Sensors, which are installed worldwide in diverse environmental conditions - from extremely hot regions to freezing cold climates, from highly humid areas to arid zones, and from tropical weather to snowy regions.

Recognizing the growing market demand, SEVEN developed a new Thermopile Pyranometer to deliver high-accuracy irradiance measurement and meet industry standards.

Features of the SEVEN Class A Thermopile Pyranometer

The Class A pyranometer of SEVEN Sensor is fully compliant with IEC 61724-1:2021 and ISO 9060:2018 standards, ensuring high-precision irradiance measurements for accurate performance ratio calculations. The low zero-offset and the minimal non-stability are key criteria that define a Class A pyranometer. To achieve these performance criteria, SEVEN developed its pyranometer by using the white diffuser instead of a traditional black body and a single dome.

What is the difference between Black Body and White diffuser for Pyranometer?

The black disc sensor has been used for decades by almost all pyranometer manufacturers. This sensor is a relatively cheap way to make a thermal sensor to absorb radiation. It is made by painting a soldered wire thermopile, a relatively cheap method. The disadvantages of this sensor is the long response time due to its size and thermal mass - about 10-20s, later the response time was artificially improved in digital models by approximating the measurements, resulting in about 5 s response time. Another big problem with this technology is the fact that the paint will change its properties with time when exposed to UV light. This happens especially strongly in the first years of use. That is the reason why pyranometers using this technology have to be recalibrated every 1-2 years.

On the other hand, using a white quartz diffuser protects the sensor from thermal effects in a similar way that the inner dome does in traditional pyranometers with a black body design. This is why the SEVEN Pyranometer requires only a single dome.

According to the ISO 9060:2018 standard, response time is a key criterion for Class A classification. Thanks to its innovative white diffuser design, the SEVEN Pyranometer offers a rapid response time of just 0.5 seconds.

Furthermore, this design is highly stable over time and does not require frequent recalibration. As a result, SEVEN recommends recalibration only once every 5 years, significantly reducing maintenance efforts and long-term operational costs.

With its innovative design, the SEVEN Class A Pyranometer enhances measurement stability, reduces thermal offsets, and improves angular response for superior data accuracy.

Additionally, the SEVEN Thermopile Pyranometer is equipped with a LED indicator.

LED Indicator for Easy Control

The LED indicator on SEVEN Pyranometer provides real-time feedback on its operational status. This ensures users can quickly verify that the sensor is functioning properly, reducing downtime and improving system reliability.

While checking a Pyranometer on site can be challenging as it generally requires to be connected to the computer which is not always available, SEVEN decided to eliminate the checks related to Power by adding a LED indicator visible on the Pyranometer. If the Green LED is on, this means that the Pyranometer is well powered and if a communication issue arises while the LED is green, users can be assured it is not power-related.

SEVEN Sensor Class A Pyranometer: High Quality Solution

To sum up, the key features & benefits of the new SEVEN Class A Pyranometer are:

International Standard Compliant -- "ISO 9060:2018, fast-response, spectrally flat and Class A" and "IEC 61724-1:2021 Class A".
White diffuser technology -- Enhances stability, minimizes temperature effects.
Fast Response -- Ensures accurate and real-time solar radiation measurements.
Built-in LED indicator -- Quick sensor checking.
Superior thermal performance -- Reduces measurement errors under fluctuating conditions.
Easy integration -- Fully compatible with SCADA systems and dataloggers.
Weather-resistant -- Designed for long-term outdoor Operation.
Fast installation -- Plug-and-play setup for minimal downtime.

With SEVEN's Class A Thermopile Pyranometer, you get the latest innovation in solar monitoring technology, ensuring accurate performance ratio calculations and optimized PV plant efficiency.

Refer to the technical datasheet for more details.