Computerized body temperature telemetry in small animals: use of simple equipment and advanced noise suppression.

Telemetric measurement of body temperatures in small animals implanted with commercially available transmitters (Mini-Mitter) has been automated using the Commodore C-64 microcomputer. Transmitter output frequencies are received by common AM-radios, converted to TTL level by a simple interface and measured by a machine language subroutine. Multiplexed input is under software control and allows for the recording of at least 16 animals selectively, with data points for each sample every 3 min. The effects of environmental electrical noise are significantly reduced by an error detection system based on the separate reception of interference.