There are two generally accepted Classification Systems used for Pyranometers. ISO classifies pyranometers as a “Secondary Standards”, “First Class” or “Second Class” while WMO uses “High Quality”, “Good Quality” and “Moderate Quality”.
The Precision Spectral Pyranometer, is classified as a ISO Secondary Standard or WMO High Quality Pyranometer.
· Classification: ISO Secondary Standard Pyranometer / WMO High Class
· Response time: 1 second (1/e signal).
· Response Time (95%): 10-15 seconds
· Zero Offset to 200 Wm-2 net radiant loss to sky: 4-6 Wm-2
· Zero Offset to 5° C/hr change in ambient temperature: 1-2 Wm-2
· Resolution: < 1 Wm-2
· Non-Stability: <0.5% / yr (typical)
· Non-Linearity: ±0.5% from 0-2800 Wm-2
· Directional Response: < 10 Wm-2
· Spectral Selectivity: 1%
· Temperature Response: ±1%
· Tilt Response: < 0.5%
· Achievable Uncertainty (Hourly): 1-2 %
· Achievable Uncertainty (Daily): 1-2 %
· Suitable Application: Working Standard or Network Measurements
· Sensitivity: approx. 9 μV/Wm-2.
· Impedance: approx. 650 Ohms.
· Temperature Dependence: ±1% over ambient temperature range -20 to +40°C
· (temperature compensation of sensitivity can be supplied over other ranges at additional charge).
· Linearity: ±0.5% from 0 to 2800 Wm-2.
· Cosine:
o ±1% from normalization 0-70° zenith angle;
o ±3% 70-80° zenith angle.
· Mechanical Vibration: tested up to 20 g's without damage.
· Calibration: integrating hemisphere.
· Size: 5.75 inch diameter, 3.75 inches high.
· Weight: 7 pounds.
· Orientation: Performance is not affected by orientation or tilt.
· A calibration certificate traceable to the World Radiation Reference and a temperature compensation curve is included.
