Title:
METHOD OF CONTROLLING FREEZER AND CONTROL DEVICE FOR FREEZER FOR THERMO-HYGROSTAT
Document Type and Number:
Japanese Patent JP3023637
Kind Code:
B2
Abstract:
PURPOSE: To prevent a disturbance in temperature control in a testing chamber caused by a variation in ambient temperature around a device, in particular, a reduction in performance of temperature where the device can reach its minimum value.
CONSTITUTION: A thermo-hygrostate is operated such that an adjusted temperature and an adjusted humidity are controlled by a heater 7 and a humidifier 8 installed within a chamber 2. Condensing means 10 and 11 and a pressure reducing means 12 are connected to an evaporator 13 installed within the chamber 2 through a compressor 9, and a freezer for use in cooling the inner region of the chamber 2 to a predetermined temperature. At this time, the compressor 9 making a cooling capability variable in response to a variation in the number of rotation in its operation is employed. There is provided a refrigerant evaporating temperature sensor 15. A frequency for changing the number of rotation of the compressor 9 is calculated and controlled in such a manner that the sensed temperature is kept at a constant target value of refrigerant evaporating temperature. With such an arrangement as above, it is possible to keep the refrigerant evaporating temperature at a constant temperature so as to be stabled and thus stabilization and high accuracy of a testing chamber temperature control can be realized.
Inventors:
Akinori Sakurai
Yasuo Kawamoto
Takeo Ogawa
Masatoshi Sakurano
Yasuo Kawamoto
Takeo Ogawa
Masatoshi Sakurano
Application Number:
JP13763793A
Publication Date:
March 21, 2000
Filing Date:
June 08, 1993
Export Citation:
Assignee:
株式会社日立製作所
日立清水エンジニアリング株式会社
日立清水エンジニアリング株式会社
International Classes:
B01L7/00; B01L7/04; F24F11/02; F25B1/00; (IPC1-7): F25B1/00; B01L7/00; B01L11/02; F24F11/02
Domestic Patent References:
| JP596185A | ||||
| JP6463774A | ||||
| JP1147259A |
Attorney, Agent or Firm:
Tatsuyuki Unuma