LOW-TEMPERATURE IN-LIQUID OBSERVATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a low-temperature in-liquid observation device which is capable of retaining heat over the entire part within the device at a specified temperature. SOLUTION: The low-temperature in-liquid observation device having a camera case 30 which houses a camera unit 19 for projecting the inside of a tank stored with a cryogenic liquid on the front and houses a control circuit board 21 on the rear side, an inner case 31 covering the camera case 30 and an outer case 33 which covers this inner case 3 through a vacuum thermally insulating layer 32 is arranged with sheet-like heaters 60 on the outer side of the camera case 30 by dividing the heaters to a plurality in the axial direction of the camera case 30 and winding the same. The respective heaters 60 are provided with temperature detecting means 61 by each of the heaters. The control circuit board 21 described above is provided with relays 46 for on - off control of the respective heaters 60 by the detected temp. of each temp. detecting means 61.