Practical Application of Outdoor Thermal Enviroumental Meter

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An outdoor thermal environmental meter has been developed for measuring total environmental solar radiation, mean radiant temperature, ambient air temperature and wind velocity in outdoor environment. Dor the application of the meter, the followings are dealt with in this study.A radius of 2cm is determined for the sphere which is the sensor of the meter. For this purpose, we make a simulation computation to estimate the fittest radius in which deviations of calculated values of the above elements are minimums. Meanwhile, the limitation of the meter is taken into account in the determination of the radius of the sphere used for the present meter.A method is described for obtaining the above four elements only by using each temperature at the centers of the four spheres. By simulation calculation, it can be realized that deviations of the four elements obtained with this method are larger than that with the previous method.Therefore, a new method can be approached by two following ways. I.e., the one is to measure the temperatures of the four spheres and ambient air temperature. The other is to measure temperatures of the four spheres and wind velocity. By comparing above ways, it can be made cleat that the latter shows smaller deviations of the calculated values.Outdoor measurements were performed with the improved meter in the unsteady conditions. Precisions of the meter are 25kcal/m^2h for the measurement of total solar radiation and 1.2゜c for the measurement of ambient air temperature. In addition, a response time to an extreme chante of solarradiation has been identified to be about 2 minutes in the measurement of total solar radiation.