Canadian Forest Service Publications
Microprocessor-controlled mini-environmental chambers capable of subfreezing temperatures in constant or time-varying temperature regimes. 1998. Gray, D.R.; Ravlin, F.W.; Logan, J.A. The Canadian Entomologist 130: 91-104.
Issued by: Laurentian Forestry Centre
Catalog ID: 16700
Availability: PDF (request by e-mail)
A set of six microprocessor-controlled mini-environmental chambers (0.04 m3 each) was designed, built, and tested. Chambers are capable of subfreezing temperatures (less than -10°C) and can operate under constant or time-varying temperature regimes. Chambers are cooled by circulating ethyl alcohol from a reservoir chilled by an immersion cooler. Heat is provided by 17-W cartridge heaters. Temperatures are independently controlled by a single IBM 8088 computer instructing a data acquisition and control system. A single photoperiod is maintained by a commercial timer activating two miniature light bulbs in each chamber. Chamber temperatures were within 0.5 or 0.75°C of the set temperature 65 or 94% of the time, respectively, during a 39-d test period. Minimum temperature capabilities were estimated for a variety of chamber configurations by an examination of the thermodynamic characteristics of the system.