Snow cover detection method and apparatus for greenhouse roof, and snow melting method and apparatus for greenhouse roof using the same

摘要

PROBLEM TO BE SOLVED: To provide means for detecting snow cover which enables snow melting with a low loss of snow melting energy by detecting the presence or absence of snow cover on a greenhouse roof inexpensively, accurately, and extensively.SOLUTION: In detecting snow cover of a greenhouse roof 14 in which temperature is managed by a heating device, the inner surface temperature (the surface temperature of a greenhouse side) of the greenhouse roof 14 is measured by a temperature sensor 40, and when the change of the inner surface temperature of the greenhouse roof 14 which is measured by the temperature sensor 40 is within a given threshold range including 0°C, it is detected that there is snow cover on the greenhouse roof 14. When the temperature sensor 40 is disposed at a plurality of positions and the number of the temperature sensors 40 indicating a value within the given threshold range is not less than a given number, it can be detected that there is snow cover.SELECTED DRAWING: Figure 7