DR02 is a high-accuracy direct (normal incidence) solar radiation sensor with a short response time. The scientific name of this instrument is pyrheliometer. DR02 pyrheliometers comply with the first class specifications of the ISO 9060 standard and the WMO Guide. DR02 pyrheliometer has a heated window and is used in tracker-mounted operation. Its fast response makes it very suitable for PV (photovoltaics)-related applications.

DR02 is a solar radiation sensor that is applied in high accuracy measurement of the solar radiation received by a plane surface from a 5 ° full field of view angle. This quantity, expressed in W/m2 , is called “direct” solar radiation or direct normal irradiance (DNI). Pyrheliometers like DR02 are generally employed outdoors under the sun. It is necessary to keep the instrument pointed at the sun by using a two-axis tracker.

Due to its short response time, DR02 is ideally suited for concentrated PV or concentrated thermal applications, where it will match the response time of the panel or receiver. Typical DR02 applications are solar energy resource assessment and system performance monitoring (in particular for concentrated solar energy), scientific solar climate observations and outdoor material testing.

Besides its short response time, DR02 offers more advantages over competing models: DR02 window assembly is equipped with a heater which increases data availability, for instance by reducing measurement errors caused by (early-morning) dew deposition. DR02 can be connected directly to commonly used data logging systems. The irradiance in W/m2 is calculated by dividing the instrument output, a small voltage, by the sensitivity. This sensitivity is provided with DR02 on its product certificate. DR02 pyrheliometer is optionally equipped with a temperature sensor and is optionally characterised for its temperature dependence. This can be used to increase the accuracy of the measurement.

Specification

Measurand : direct solar radiation ISO classification : first class pyrheliometer Response time (95 %) : 2 s (nominal) Total sensor length including cap : 380 x 10^-3 m Full field of view angle : 5 ° Slope angle : 1 ° Calibration uncertainty : < 1.2 % (k = 2) Calibration traceability : to WRR Measurement range : 0 to 4000 W/m² Spectral range : (50 % transmission points) 200 to 4000 x 10^-9 m Sensitivity (nominal) : 10 x 10^-6 V/(W/m²) Rated operating temperature range : -40 to +80 °C Temperature response : < ± 1 % (-10 to +40 °C) Temperature response : < ± 0.4 % (-30 to +50 °C) with correction in data processing, if opted for internal temperature sensor + temperature dependence characterisation Window assembly with heater : 12 VDC, 0.5 W Standard cable length : 5 m (see options)