Actinometry

Actinometry - devices for measurement of intensity of radiant energy. Most actinometric based on the principle of measurement of the thermal effect in the transformation of radiant energy into heat. The amount of radiant energy is expressed in small calories absorbed in 1 minute surface in 1 cm2 (cal/cm2·min), located perpendicularly to the direction of the rays.
The intensity of solar radiation to penetrate her in the earth's atmosphere is called the solar constant. Reaching the earth's surface part of the radiant energy of the sun (direct solar radiation) together with the part of solar radiation falling after dispersion in the atmosphere (diffuse radiation)is the total solar radiation. Part of the radiation reflected from the earth surface, is called the reflected.
Scattered and total solar radiation is measured by pyranometers. One of the variants of the device - the pyranometer Kalitina consists of two thermometers, with a different cover (often and magnesium oxide). The intensity of total solar radiation (Q) is defined by the difference of heating black (t) and coated magnesium oxide (t1) thermometers. Q=(t-t1)·K, where K - the conversion factor C in calories. Pyranometric adapted to measure the reflected from the earth's radiant energy, called albedometer. For the measurement of direct solar radiation in relative units (on the beaches and sun decks) applies actinometer Mikhelson. Devices for measurement of direct solar radiation in absolute units (cal/cm2·min) called pyrheliometers.
For sanitary-hygienic examination of the sources of radiant energy in a production environment using various technical actinometry type actinometer Noskov or Supervisory actinometer LIT-N (Fig). The reception part of actinometer LIT-N is made of aluminum foil, which is applied to the strip often. From black and shiny foil plots are junctions of thermopile to the galvanometer. The scale of the galvanometer respectively graded.

inspection actinometer LIT-N
Inspection actinometer LIT-N: 1 - General view; 2 - the reception part.

Actinometry (from the Greek. aktis, aktinos - ray and metreo " measure") - devices for measurement of intensity of radiant energy. The majority A. based on the principle of measurement of the thermal effect in the transformation of radiant energy into heat. Scattered and total solar radiation is measured by pyranometers. The most common and simple in design is a pyranometer Kalitina (Fig. 1). The action of the pyranometer Janiszewski (Fig. 2) based on the principle of measuring thermotoga arising in a heated under the influence of radiation blacked out and coated magnesium oxide the junctions of the thermopile. Pyranometric adapted to measure the reflected from the earth radiation are called albedometer. The most common albedometer Janiszewski - Catch (Fig. 3) has the same receiver, as the pyranometer Janiszewski. Actinometer Mikhelson, measure sipakou solar radiation in relative units, convenient for work on the beaches and in the Solarium (Fig. 4).
Receiver it is enclosed in the unit bimetallic strip (from iron and Inara), blackened by iron. Under the action of radiation iron expanding and rejects the free end of the plate in the direction of Invar. This bias is reinforced by the arrow ending quartz thread. Offset filaments observed in the microscope on a scale of micrometer, serves as a measure of radiation.
Devices for measurement of direct solar radiation in absolute terms Cal/cm2·min - called pyrheliometers. A control device for all existing A. is pyrheliometer Angstrem (Fig. 5). Radiation artificial (production) sources of technical measure A.; of these, the most common actinometer Noskov, or inspection actinometer LIT-N (Fig. 6). His successor covered with aluminum foil, to blackened areas which joined the "hot", and by brilliant - cold junctions of the thermopile (200 junctions). The intensity of thermotoga is determined by a galvanometer. Actinometer Kalitina has bimetallic receiver from Constantan and Inara (Fig. 7). The deflection of Konstantinovo plate when exposed to radiation is transmitted to the arrow of the device by the system of levers. Recalculation of deviations arrow in cal/cm2·min is made according to the nomogram. For measuring small values of radiation and radiation of the body used termoprint moll and radiometer Boyko.


the pyranometer Kalitin
Fig. 1. The Pyranometer Kalitina.

the pyranometer Janiszewski
Fig. 2. The pyranometer Janiszewski: 1 - removable tile; 1 - glass hemisphere; 3 - cap, used to determine the place of zero; 4 - level; 5 - screw for the direction of the pyranometer towards the sun; in - set screws; 7 - screen; 8 - terminal to enable dial galvanometer.

albedometer Janiszewski-Catch
Fig. 3. Albedometer Janiszewski-Catch: 1 - cylinder, with the thermopile; 2 - cardan suspension; 3 - arm; 4 - tube.
actinometer Michaelson
Fig. 4. Actinometer Mikhelson.

compensation pyrheliometer Angstrem
Fig. 5. Compensation pyrheliometer Angstrem (scheme): 1 and 2 - manganin plate; 3 and 4 - the thermocouple junctions; 5 - switch; 6 - cell battery; 7 - galvanometer; 8 - milliammeter; 9 - a rheostat.


Fig. 6. Inspection actinometer LIT-N.

actinometer Kalitin
Fig. 7. Actinometer Kalitina: a - appearance; b diagram of the device: 1 - the disc from Constantan; 2 - plate of Invar; 3 and 4 - hours; 5 - arrow; 6 - axis.