Improvement upon the Indicating Charac飴rsof a Hot Wire Anemometer

The authors have been carring on the studies on a hot wire anemometer by the use of a Pt-wireand Wheatstone's bridge，a nd it was already reported that the indicating characters were improved to such an extent for practical use. As the characteristics， however，were not linear，we tried to use a thermistor instead of the Pt-wire for the measuring head of the anemometer in this paper. As the result，linear characteristic was obtaind for the wide range beyond 0.6m/s，but for the lower velocity less than 0.6m/s，the sensitiveness of the meter was decreased with the decreasing velocity. In order to improve the weak point，new type of the measuring head which was constructed by the thermistor，the Pt-wire and the screen with 20 meshes was introduced. In such away，we obtained a hot wire anemometer with the linear character for the wide range of the air velocity. At present，some problems are being studied such as an effect of air temperature and indicating response etc.