Frozen and melt test is advisable,but when frozen and dilated soil melts,the bottom of the frozen and melt tube touches indoor floor which is not completely in conformity with the law of simulated ature melt,in order to avoid this case,increasing the bottom of preventive heat tube,meanwhile,improving the range finder and calcalating method,enhancing the calculating precision.

Temperature compensation circuit design of ultrasonic measuring distance system Based on the single chip processor;

Practical application of voltage traveling wave measuring distance principle in Ningxia Power Grid;

The introducing and initial application of ranging and amendment method;

Error Analysis of a USB Ranging System;