Design of double layer resistance gird SOI strainometer and its application in coal mine

A double layer resistance gird SOI strainometer with micro fuse structure was designed. The strainometer is produced by techniques of thermally grown oxide, photoetching and mechanical erosion. It solves problems of normal SOI strainometer which has small bulk resistor and is vulnerable to pollution, and improves precision, insulativity and working stability of the strainometer. Field test results show that mine borehole stressmeter adopting the proposed SOI strainometer has high measuring accuracy and stable and reliable performance,and is suitable for stress monitoring of coal and rock mass.