A Growth Cabinet for the Study on Biotronics

Abstract

For studies on biotronics of fundamental problems in environmental control in biology, high accurate control of environmental factors was demanded. The growth cabinet is considered as an effective tool for such purpose. Present report deals with a trial to develop a growth cabinet with capacity of high accurate control, and following results were obtained.1) It became possible to control temperature from -5°C to 40°C with accuracy of ± 0.5°C. The P. I. D. control action contributed to remove off-set and cyclic variation in temperature control. In the case of program control, temperature gradient of 10°C/30 min was obtained.2) Relative humidity was controlled from 40% to 80%±3% at temperature range from 10°C to 40°C. In program control, falling and rising gradient of relative humidity was 10%/15 min.3) Wind direction, velocity and distribution were kept uniform by 16 fans installed at the side of air supply compartment. Wind velocity ranged from 0.2 m/sec to 0.5 m/sec.4) The canopy provided 45 fluorescent lamps of 40 W (FLR40S·W-SDL-AP/M) and 8 incandescent lamps of 100 W. At 50 cm above floor 20, 000 lux (110μW/mm2) of light intensity was obtained. However, it is not clear whether the spectrum distribution of the light is suitable for plant, or not.