摘要：基于双混频时差技术设计研制了8通道的频率稳定度测量系统,实现了对8路5 MHz或10 MHz频率标准的测量.当频率为10 MHz取样时间为1 s时,系统噪声本底优于2.0 X 10^(-13),取样时间为1000 s时,系统噪声本底优于2.5×10^(-16).不但可以满足原子时标基准原子钟组的内部比对,也可实现对一般频率标准的检定和校准.Abstract：Based on the technique of Dual Mixer Time Difference (DMTD), an 8-channel frequency stabilitymeasurement system has been developed. It realized the measurement of 8-channel 5 MHz and 10 MHz frequencystandards. For 10 MHz frequency, the noise floor is better than 2.0 ×10^(-13)/1 s, 2.5× 10^(-16)/1000 s. It can not only satisfy the internal comparison of time scale ensemble, but also can realize the calibration of normal frequency standards.

摘要：本文介绍了车用燃油空气加热器选择的参考因素，简要叙述了特种设备车辆安装车用燃油空气加热器时应注意的事项和安装建议，提出了加热器试验要求和安全使用要求，可作为车用燃油加热器安装设计时的参考。