Eppley Laboratory 8-48 Black White Pyranometer Diffuse Radiometer 295-2800nm

Eppley Laboratory 8-48 Black White Pyranometer Diffuse Radiometer 295-2800nm

The Eppley Laboratory Model 8-48 is a Black & White Pyranometer designed for measuring diffuse (scattered sky) solar radiation. It uses a thermopile detector with alternating black and white segments beneath a precision glass dome to measure incoming shortwave irradiance across a spectral range of 295–2800 nm. Unlike all-black pyranometers, the black-and-white design eliminates the thermal offset inherent in all-black sensors, making it the preferred instrument when deployed in the shaded (diffuse) position in high-quality radiation measurement networks.

Specifications & What's Included

• Manufacturer: Eppley Laboratory, Newport, Rhode Island
• Model: 8-48 (Black & White Pyranometer)
• Application: Network measurements — Diffuse (shaded) solar radiation
• Traceability: World Radiation Reference (WRR)
• Spectral Range: 295–2800 nm
• Output: 0–10 mV analog
• Sensitivity: approx. 8 µV / W·m⁻²
• Impedance: approx. 350 Ω
• 95% Response Time: 30 seconds
• Zero Offset A (thermal radiation): 1 W·m⁻²
• Zero Offset B (temperature change, 5 K/hr): 2 W·m⁻²
• Non-Stability (change per year): 1%
• Non-Linearity (up to 1400 W·m⁻²): 1%
• Directional Response (up to 80° at 1000 W·m⁻²): 30 W·m⁻²
• Spectral Selectivity (0.3–3 µm): 2%
• Operating Temperature: -50°C to +80°C
• Temperature Response (-20°C to +40°C): 1.5%
• Tilt Response (0° to 90°): 3%
• Measurement Uncertainty — Hourly Average: approx. 3–5%
• Measurement Uncertainty — Daily Average: approx. 3%
• Connector: Multi-pin circular connector on instrument body
• Includes: Instrument with leveling bubble and knurled adjustment hardware; multi-pin output cable with XLR-style connector (visible in photos)

Applications

The Eppley 8-48 Black & White Pyranometer is a standard instrument in precision solar radiation monitoring networks operated by meteorological agencies, atmospheric research institutions, and universities worldwide. In a standard three-component radiation measurement setup, the 8-48 is mounted beneath a shading disc or ball to measure diffuse horizontal irradiance (DHI) — the component of solar radiation that reaches the surface after being scattered by the atmosphere, clouds, and aerosols. This diffuse component, combined with direct normal irradiance (DNI) and global horizontal irradiance (GHI) data, is essential for solar resource assessment, climate research, and the validation of satellite-derived irradiance products. The 8-48 has been in continuous use in networks such as NOAA's Surface Radiation Budget Network (SURFRAD), BSRN (Baseline Surface Radiation Network), and other WMO-affiliated stations. Its WRR traceability links measurements to the international standard maintained at the World Radiation Centre in Davos, Switzerland, ensuring comparability across global networks. These instruments are also used in agricultural meteorology, building energy modeling, and photovoltaic system performance analysis.