SRA20-D2 albedometer

SRA20-D2 digital secondary standard albedometer
Digital secondary standard albedometer

SRA20-D2 albedometer is an instrument that measures global and reflected solar radiation and the solar albedo, or solar reflectance, with the highest accuracy. It is composed of two SR20-D2 secondary standard pyranometers, one sun screen, one glare screen and one fixture with rod. Mounting hardware and tools are included. Each pyranometer offers two types of commonly used irradiance outputs: digital via Modbus RTU over RS-485 and analogue 4-20 mA (current loop). Individually tested for temperature and directional response, SRA20-D2 is the most accurate digital secondary standard albedometer available. SRA20-D2 complies with the latest ISO and WMO standards. The modular design facilitates maintenance and calibration.

Specifications
Measurand
  • global solar radiation and reflected solar radiation
Optional measurand
  • albedo or solar reflectance
  • net solar radiation
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Specifications

Measurand
  • global solar radiation and reflected solar radiation
Measurement range
  • 0 to 2000 W/m²
Optional measurand
  • albedo or solar reflectance
  • net solar radiation
Included sensors
  • 2 x identical ISO 9060 secondary standard pyranometer
Mounting
  • mounting rod with 15 x 10⁻³ m diameter
Calibration uncertainty
  • < 1.2 % (k = 2)
Calibration traceability
  • to WRR
Spectral range
  • 285 to 3000 x 10⁻⁹ m
Rated operating temperature range
  • -40 to +80 °C
Temperature response
  • < ± 0.4 % (-30 to +50 °C)
Temperature response test and directional response test of individual instrument
  • reports included
Standard cable length
  • 2 x 5 m (see options)
Digital output
  • :
Output
  • -irradiance in W/m²
Output
  • -instrument body temperature in °C
Communication protocol
  • Modbus over 2-wire RS-485
Transmission mode
  • RTU
Rated operating voltage
  • 5 to 30 VDC range
Power consumption
  • < 150 x 10⁻³ W at 12 VDC (in total)
4-20 mA output
  • :
Output
  • irradiance in W/m²
Transmitted range of 4-20 mA output
  • 0 to 1600 W/m²
Rated operating voltage of 4-20 mA output
  • 5.5 to 40 VDC range
Power consumption
  • :
- main supply
  • < 150 x 10⁻³ W at 12 VDC (in total)
- 4-20 mA current loop
  • < 80 x 10⁻³ W at 12 VDC, with recommended 2 x 100 Ω shunt resistors
Options
  • longer cables, in multiples of 5 m, cable lengths above 20 m in multiples of 10 m
Manuals & Downloads

Description

SRA20-D2 digital secondary standard albedometer

Albedo, also called solar reflectance, is defined as the ratio of the reflected to the global radiation. The solar albedo depends on the directional distribution of incoming radiation and on surface properties at ground level. Albedos of typical surfaces range from about 4 % for fresh asphalt, and 15 % for green grass to 90 % for fresh snow.

Using SRA20-D2 albedometer is easy. The instrument is composed of two SRA20-D2 digital secondary standard pyranometers; the upfacing one measuring global solar radiation, the downfacing one measuring reflected solar radiation. SRA20-D2 offers two types of outputs commonly used in the solar PV industry: digital via Modbus RTU over RS-485 and analogue 4-20 mA (current loop). These industry standards allow for easy data acquisition, easy read-out and error-free instrument exchange when using SRA20-D2. The working principle and specifications of the pyranometers can be found in the SR20-D2 user manual. We recommend to use SRA20-D2 in particular in applications where the highest measurement accuracy is required.

Suggested use

  • PV monitoring with Bifacial solar modules
  • high-accuracy meteorological observations
  • building physics, roof reflectance studies
  • extreme climates (tropical / polar)
SRA20-D2 albedometer
SRA20-D2 digital secondary standard albedometer
  • digital outputs: easy implementation & servicing
  • best-in-class temperature response
  • test certificates for temperature- and directional response included as required by ISO 9060
  • re-calibration registers fully accessible to users
  • modular; can be calibrated as separate pyranometers
Would you like a personalised quote?

or contact us: info@hukseflux.com