Natural water thermal radiation at a 8 mmwavelength

Abstract

The natural water thermal radiation in the temperature range of 30-85 degrees Celsius at a wavelength of 8 mm has been experimentally investigated. The measurements were carried out on an experimental installation with a radiometer as a receiver of thermal radiation with a sensitivity of 0.2 Kelvin. The water temperature was measured by a contact thermometer immersed in the water column. The dependence of the radio brightness temperature from the water thermodynamic temperature has been established. It was shown that the dependence of water radio brightness temperature from water thermodynamic temperature is non-linear, which corresponds to theoretical concepts. It was noted that the thermal radio emission is different sufficiently in the studied temperature ranges. In the thermodynamic temperature range of 30-50 degrees Celsius the gradient of the radio brightness temperature was about 0.15 Kelvin per degree Celsius, at 55-85 degrees - about 0.6 Kelvin per degree Celsius. It was shown, that the practical use of temperature dependences of water thermal radiation is possible for monitoring of water systems.