Mätsystem för den operativa temperaturen – test av hemtillverkade globtermometrar

Sammanfattning: The thermal climate experience is most affected by air temperature that is easy to measure with a standard thermometer, but to find out how the temperature in a room is felt it is not enough to merely examine the air temperature. Even if the air temperature is at a comforta-ble level, then a cold surface near get the person to feel that it is chilly in the room and cor-respondingly the hot surfaces or solar radiation make the person feel warm even though the thermometer shows an acceptable level. Therefore, one must also take into account the surrounding surfaces’ radiant heat and com-mon method to measure the radiation contribution to climate measurement is to use the globe thermometer. The instrument is simple and practically valuable to get a physiologically adequate measure of the combined effect of air temperature and radiant heat, which is called the globe temperature. Globe thermometer is designed as a black air filled black paint-ed globe sphere with a thermocouple in the centre. Air movement can affect the human perception of temperature and time is measured using an air speedometer. With the air temperature, globe temperature and air velocity one can calculate the average radiation temperature. The operative temperature in a room is a combination of air temper-ature and average radiation temperature at a specific point, and it can be counted with three different calculation methods. In this study, a globe thermometer with an air velocity- and air temperature thermometer from Swema will be used for measuring the operative temperature. Furthermore seven homemade globe thermometers with external sensors that measure air velocity and air tem-perature will be used for the same purpose. At the same time a check will be performed on the operating temperature to see if it meets the recommended comfort requirements in cli-mate. The saturation was conducted on three different occasions twice in an office room both winter and summer, moreover in a classroom during the summer. By comparing the results of the globe temperature and operative temperature of the seven homemade globes the latter yielded acceptable results which were close to what Swema’s advanced equipment provided.