Development of laser interferometer strain-seismometer

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We developed the strain-seismometer which used a laser interferometer in this project. This year, we did observation with this super long period seismometer and did comparison with a record of quartz pipe strain meter and STS -1 type broad-band seismometer.As a result it does not extend to performance of a STS -1 type seismometer.We can get a good record by revising atmospheric pressure and a change of minute temperature in an observation trench. The cause of noise is understood that it was warp of the laser interferometer by around 1/100 deg.temperature change in a trench by observation of temperature by an exact thermometer and observation of atmospheric pressure change by a micro-barometer.The developed strain seismometer seems to do warp by temperature more greatly, because various kinds of materials are used every a part by difficulty and a price of production. I have to build the system which is not influenced in a temperature change by materials of super iron-nickel alloy with a little temperature changes.