A pyrheliometer is a device used to quantify the direct sunbeam of solar insolation. Sunrays enter the windowpanes and are oriented onto an instrument called a thermopile.
A thermopile consists of thermocouples, which are connected in series. These are also, commonly referred to as Parallel. A thermopile transmutes thermal energy into electric signals. A pyrheliometer is a measuring instrument, which uses a formula to convert signal voltage to calculate watts per squared meter.
Pyrheliometer used with solar tracking systems
A pyrheliometer is used in combination with a Solar Tracking system. This helps in keeping the instrument aimed at the sun.
The International Organization for Standardization and the World Meteorological Organization stipulates the standards for Pyrheliometer measurements. To measure the quantity of solar energy coming in directly from the Sun, regular comparisons are made between different Pyrheliometers. Also these standards are applied to intercalibrate these instruments.
The main objective of International Pyrheliometer Comparisons, which is conducted after every five years, at the World Radiation Center, situated in Davos is to assure the transfer of World Radiometric Reference across the world. All participants bring their solar tracking devices, instruments and all other acquisition systems while the event is being conducted at Davos. With these instruments, solar radiations are simultaneously measured with the World Standard Group.
A typical pyrheliometer is used for meteorological, scientific and climatic observations. It also evaluates and assesses the effectiveness of Photovoltaic instruments and solar collectors.
There are two types of Pyrheliometers:
SHP1: it is a pyrheliometer device well equipped with an interface having both digitized RS 485 Modbus and an intensified analogue output. This pyrheliometer offers a smart interface and is an advancement of the CPH 1 version. Moreover, the SHP1 also has a response period below 2 seconds. The individually measure temperature correction varies from negative 40°C to positive 70°C.
CHP 1: This type of pyrheilometer completely complies with the latest standards set by International Standardization Organization (ISO) and World Meteorological Organization (WMO) regarding the criteria for First Class Normal Incidence Pyrheliometer. Each pyrheliometer is checked for manufacturing and supply standards with a traceable checking certificate issued by the World Radiometric Reference (WRD).
Pyrheliometer is generally used to analyze the variations in solar radiation productivity. Another function of the pyrheliometer is the solar panel design and placement.
Different amounts of solar irradiance reaches diverse parts of the Earth, so these pyrheilometers come in handy to create average radiation level maps. With the creation of these maps, the appropriate placement of solar panels can be identified.