Lefcourt A M, Bitman J, Wood D L, Stroud B
J Dairy Sci. 1986 Jan;69(1):237-42. doi: 10.3168/jds.S0022-0302(86)80391-5.
Deep body temperature is an important index of the physiological status of an animal. A radiotelemetry system was developed to monitor continuously udder and body temperatures in cows under normal housing conditions. Radiotransmitters were crystal controlled blocking oscillators operating in the 27 MHz band. Functionally, the transmitters turned on and off in a pulsatile fashion with temperature encoded as the time interval between two pulses (nominally .5 s at 38 degrees C). Transmitters were powered by lithium batteries (6-mo lifespan) and were encapsulated in paraffin/Elvax (cylinder 6 cm X 3 cm diameter). Signals were detected using a radio receiver in the AM mode. Reception frequency was selected by computer. Each audio pulse was electronically converted to a digital pulse. A PDP 11/23 computer converted intervals between digital pulses to temperature values. As finally configured, the computer collected data from 12 transmitters every 1.4 min (1024 readings/transmitter/d). Temperatures were graphed continuously and stored on magnetic media for future analyses.
深部体温是动物生理状态的一个重要指标。开发了一种无线电遥测系统，用于在正常饲养条件下连续监测奶牛的乳房温度和体温。无线电发射器是晶体控制的阻塞振荡器，工作在27兆赫兹频段。在功能上，发射器以脉动方式开启和关闭，温度编码为两个脉冲之间的时间间隔（在38摄氏度时标称值为0.5秒）。发射器由锂电池供电（寿命为6个月），并封装在石蜡/乙烯-醋酸乙烯共聚物中（直径6厘米×3厘米的圆柱体）。使用调幅模式的无线电接收器检测信号。接收频率由计算机选择。每个音频脉冲被电子转换为数字脉冲。一台PDP 11/23计算机将数字脉冲之间的时间间隔转换为温度值。最终配置的计算机每1.4分钟从12个发射器收集一次数据（每个发射器每天1024次读数）。温度被连续绘制成图表，并存储在磁介质上以供未来分析。
