Actinometer - Solar Radiation tool - free to use
what is Actinometer " Solar Radiation tool " ?
An actinometer is a gadget that is utilized to quantify the force of sun powered radiation. It is a substance framework that decides the quantity of photons by measuring the rate of progress of photoinduced reactions in a concoction framework.
The actinometer was first designed by John Herschel in 1825. It works in view of the rule that the rate of photolytical change of atoms inside an actinometer cell is equivalent to the rate of ingestion of photons in the actinometer.
A physical gadget, for example, a bolometer, photodiode and photomultiplier is utilized to change over the episode photon vitality into a quantifiable electrical flag. Be that as it may, a concoction actinometer is the most broadly utilized gadget in which the quantum yield of a reference substance experiencing a photochemical response is resolved and aligned.
For an effective actinometer, this quantum yield must be autonomous of oxygen, follow polluting influences, temperature and excitation wavelength.
basic steps employed in the working principle of chemical actinometer
:
The gas of interest is filled into a photolysis reactor.
The actinometer is exposed to heat radiation.
The photochemical rate was measured.
Here, the actinometer gas is exposed to actinic flux without altering the radiation intensity and spectral composition significantly. For this reason, a transparent quartz cell having a suitable geometrical shape is employed, and gases with small optical absorbance values are used. Based on these conditions, the photolysis frequency can be easily evaluated.
There are two basic modes of actinometric operation: static batch mode and flowing gas mode. In the static batch mode, the photolysis reactor is filled with actinometer gas, sealed off by a gas valve and covered with an opaque hood to prevent exposure to sunlight.
During measurement, the actinometer is uncovered and exposed to heat radiation for a fixed interval of time. Following this, the actinometer is closed again and analyzed for change in the gas composition.
In the other mode of operation, the actinometer gas is constantly passed into the reactor that is exposed to solar radiation. In this case, the time interval is considered to be the mean residence time of the gas in the illuminated reactor.
When the gas passes through the reactor, its composition is analyzed using an online gas detector. Photolysis frequencies can be continuously monitored in this mode.
Applications
The actinometers are chiefly used in meteorology to measure solar radiation transmitted by the sun, reflected by the earth or scattered by the atmosphere. They are used in photochemical experiments that involve complex irradiation geometry. In addition, actinometers serve as a first choice for calibrating photochemical detectors used for radiation measurements.
These tools can be united with joulemeters for measuring laser pulse energies. The actinometers tend to lose sensitivity and precision at high laser pulses owing to various photon processes taking place at high photon densities. However, repeated calibration of actinometers with controlled accuracy can be ensured upon the realization of linearity of the joulemeter readout.
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