PRESENTED BY: -ANSHUL SHRIVASTAVA

M.TECH (POWER DISTRIBUTION WITH SPECIALIZATION IN SMART GRID)

UNIVERSITY OF PETROLEUM & ENERGY STUDIES,DEHRADUN

PyranometerPyrheliometer

Introduction

A pyranometer is a typeof “actinometer” used to measure broadband solar “irradianceon” a planar surface and is a sensor that is designed to measure the solar radiation flux density (W/m2) from a field of view of 180 degrees.

Also called “Directional Response” or “Cosine Response”.

Explanation

A thermopile sensor with a black coating. This sensor absorbs all solar radiation, has a flat spectrum covering the 300 to 50,000 nanometer range, and has a near-perfect cosine response.

A glass dome. This dome limits the spectral response from 300 to 2,800 nanometers, while preserving the 180 degrees field of view. Another function of the dome is that it shields the thermopile sensor from convection.

Cont..

The black coating on the thermopile sensor absorbs the solar radiation. This radiation is converted to heat. The heat flows through the sensor to the Pyranometer housing. The thermopile sensor generates a voltage output signal that is proportional to the solar radiation.

Application

MeteorologyClimatologySolar energy studiesBuilding physics

Pyrheliometer

A Pyrheliometer is an instrument for measurement of direct beam solar irradiance.

Sunlight enters the instrument through a window and is directed on a thermopile which converts heat to an electrical signal that can be recorded.

Cont..

The signal voltage is converted via a formula to measure watts per square meter.

 It is used with a solar tracking system to keep the instrument aimed at the sun.

Application

Scientific meteorologicalClimate observationsMaterial testing researchAssessment of the efficiency of solar collectors and photovoltaic devices.

Difference

Pyranometer is a dome like structure that measures diffused sun energy while Pyrheliometer is an instrument that measures direct sun’s energy.

Both are often used in conjunction in meteorological research stations.

Pyrheliometer helps in assessing the efficiency of solar panels