Metal ring SHR02

Overview
The SHR02 is a practical metal shadow ring designed to enable diffuse solar irradiance measurements when combined with a pyranometer, together forming a diffusometer in accordance with the ISO 9060:2018 standard. The shadow ring (also known as a shadow band) prevents direct solar radiation from reaching the pyranometer detector so that the shaded pyranometer measures diffuse radiation only. It serves as a compact, low-investment alternative to a sun tracker with a shading disc and is compatible with most Hukx pyranometers. Featuring an incorporated tilt adjustment stage, the SHR02 allows diffuse irradiance to be measured either horizontally or in a tilted plane, while manual adjustment of its sliding bars compensates for the seasonal change in solar altitude.

Key features
• Diffusometer assembly: combines with a pyranometer to measure diffuse solar irradiance without requiring an expensive automated sun tracker.
• Low-offset measurement performance: optimized for use with low-zero-offset pyranometers (such as the heated and ventilated SR30 or heated SR25), achieving high measurement accuracy and eliminating the need for bulky external ventilation units.
• Incorporated tilt adjustment stage: enables diffuse solar radiation measurements in horizontal as well as tilted planes, with an engraved latitude/rotation scale.
• Seasonal solar compensation: features adjustable sliding bars with engraved millimeter scales to manually correct the ring height for changing solar declination throughout the year.
• U-profile ring with stabilized view angle: engineered with side rims to provide mechanical rigidity and minimize the seasonal variation of the average 10.6° view angle to less than 2 %.
• Safe sliding adjustment: sliding bars and thumbscrews are designed to prevent the shadow ring from sliding down abruptly when loosened simultaneously.
• Standards compliance: meets recommended operational practices defined by ISO/TR 9901, WMO-No. 8 (shading ring recommendations), and ASTM G183-05.

Applications
• Diffuse horizontal irradiance (DHI) monitoring in meteorological and climatological networks.
• Solar energy studies and solar resource assessments (combined with GHI to estimate Direct Normal Irradiance, DNI).
• Photovoltaic (PV) system performance monitoring (horizontal and tilted Plane of Array diffuse measurements).
• Building energy performance and architectural physics research.

Specifications
• Function: forming a diffusometer when combined with a pyranometer
• Diffusometer measurand: diffuse solar radiation [W/m²]
• Diffusometer measurand in SI radiometry units: irradiance in W/m²
• Expected diffuse irradiance range: 0 to 250 W/m²
• Instrument compatibility (standard): SR30, SR15 pyranometers
• Instrument compatibility (with optional adapter): SR20, SR22, SR25 pyranometers
• Zero offset a of diffusometer assembly:
• With SR30: 2 W/m²
• With SR15: 5 W/m²
• With SR25: 1 W/m²
• With SR20: 5 W/m²
• Ring inner diameter: 476 x 10⁻³ m
• Ring width: 44 x 10⁻³ m
• Ring rim height: 20 x 10⁻³ m
• Ring profile: U-profile
• Average view angle: 10.6°
• Maximum diameter of shaded area: 40 x 10⁻³ m
• Pyranometer tilt angle range: -90 to +90°
• Sliding bar range: ±110 x 10⁻³ m (resolution: 1 x 10⁻³ m; accuracy: ±0.5 x 10⁻³ m)
• Base plate diameter: 250 x 10⁻³ m
• Bounding dimensions (H x D x W): 770 x 725 x 516 x 10⁻³ m
• Net weight: approx. 4 kg
• Construction materials: anodized aluminum (main elements and black parts with organic dye); fasteners in stainless steel A4
• Rated operating temperature range: -40 to +80 °C
• Leveling: integrated bubble level (< 0.1° accuracy) and leveling set screws included

Options and accessories
• PMA01: mounting adapter for installing SR20, SR22, and SR25 pyranometers on SHR02
• Standard delivery fasteners: spring-loaded M8 leveling mounting set (bolts, springs, washers, and nuts) and socket set screws