ATMOSPHERIC PRESSURE MEASUREMENT BY MEANS OF VARIATION OF BOILING POINT OF WATER

摘要

For the purpose of estimating the ventilating pressure in tunnels,atmospheric pressure of several locations in tunnels were measuredby using a well-known barometer. But there are some difficulties ingetting the accuracy of measurements.This paper deals with a measuring device of atmospheric pressurebased on variation of boilib points of water. Such devices alreadyhave been studied, but never have we heard of its utilization. It isthe reason why the temperature of boiling points is depended on theposition where the temperature sensor is placed. So the authors madean attempt to use the float on which the temperature sensor is attached.In this way, temperature of the sensor could be kept moresteable than that without the float. As the results, it was foundthat the variation of the atmospheric pressure, about 2 mmAq, couldbe measured by using this device.