环境温度对地震数据采集器时间精度的影响测试

为适应地震数据采集器时间精度测试的需要，采用特定电路将普通参考时钟源输出的分脉冲信号扩展至占空比为50%，再利用扩展后的分脉冲信号在室温、低温恒温及高温恒温环境中对地震数据采集器时间精度进行测试，研究环境温度对地震数据采集器时间精度的影响。结果表明，地震数据采集器时间精度及漂移趋势受环境温度变化影响，0.5 h内发生约1 ℃的温度变化可引起地震数据采集器产生μs级时钟精度变化和守时趋势变化，通过温度对时间数值积分反映的温度变化累积效应与地震数据采集器时钟漂移的趋势变化具有较好的对应关系；恒温环境下地震数据采集器的时标延迟变化表现出单调特性，变化率由个体使用的晶振器件决定，并与环境温度有关。

Testing of Ambient Temperature Influence on Time Tag Accuracy of Seismic Digitizer

To meet the needs of time accuracy testing of seismic digitizer, we use a specific circuit to extend the PPM(pulse per minute) output by the common reference clock source to a duty cycle of 50%. With the extended PPM, the time tag accuracy of seismic digitizer is tested at room temperature, constant low temperature and constant high temperature environments. We study the influence of ambient temperature on time tag accuracy. The results show that time tag accuracy and drift trend of seismic digitizer are affected by the change of ambient temperature. A temperature change of about 1 ℃ in half an hour can cause the time tag accuracy change of microsecond stage and the drift trend change of time tag delay. The cumulative effect of temperature change reflected by temperature to time numerical integration has good correspondence with the drift trend change of seismic digitizer. The time tag delay at constant temperature environment shows monotonous characteristics. The drift rate is determined by the crystal resonators used by individual digitizer, and it is associated with the ambient temperature.