An automatic control device to regulate at subzero temperatures

device to regulate at subzero temperatures. J. Appl. Physiol. 27(4) : 552-553. 1969.-A simple and effective automatic temperature regu-lator is described which uses Dry Ice and a heating element to control temperature of frozen central nervous system tissue for purposes of fine dissection. Dry Ice acts as a heat sink and a solid-state servo system applies an appropriate amount of heat inflow to maintain preset temperatures (usually- 18 to-20 C) within zko.5 c. temperature control; temperature regulator; cryostat; tissue dis-section FOUR YEARS AGO we published a circuit (4) which was an improve-ment over the KrnjeviE and Mitchell (3) circuit for maintaining constant body temperature of experimental animals. Both the performance and reliability of the new device have been excellent. Heat loads ranging from small mineral oil pools (approximatel