Global Radiation Flashcards
1
Q
The global sun spectrum impinging on earth surface can be distinguished into
two parts
A
Direct and Diffuse Radiation
2
Q
Direct
A
The sunlight hits the earth directly
3
Q
Diffuse
A
Scattering at gas molecules, aerosoles, water droplets, dust, absorption of gases
4
Q
3 types of measurement of Radiation
A
Global Radiation
Direct Radiation
Diffuse Radiation
5
Q
Principle of Pyranometer
A
- Measurement of Global Radiation
- Thermopile instrument
- Double shell glass cover
- Slow response time
- Chain of thermocouples
6
Q
Pyrheliometer
A
- Measurement Direct Irradiation
- Narrow view angle has
to track sun - Two-axis tracking
- High maintenance
requirements - Best accuracy
7
Q
Shadow Band
A
- Measurement Diffuse Irradiation
- Diffuse radiation using pyranometer by excluding direct component
- Needs every few days maintenance for adjusting shadow band
- Shadow band and Pyranometer main components
- Data corrections necessary
8
Q
Name the 3 measurement tools and to which it belongs
A
- Pyranometer - Global Radiation
- PyrHeliometer - Direct Radiation
- Shadow Band - Diffuse Radiation
