The Calibration Results of Hot-film Flow Meter

A great number of mesurment instrument of flow have been used in hydraulic engineering. For example, they are Total head tube, Rolling-propeller, Hot-wire, Hot-film, Electro-magnetic-Inductive Force, Super-sound wave, Laser flowmeter and so forth. Hot-film flowmeter is the better instrument so far developed for analysis of space and time variables of the micro structures of the velocity of a streaming liquid. The reasons of the present superior of Hot-film flowmeter as a measuring instrument for studied of liquid flows is that the flow probe sensor is sensitive, responsive and can be manifactural in exceedingly small physical sizes. In constrast to that superior caracteristics there is a few problem of measuring steadiness. One of a few problem is need of calibration of flow velocity from the existance of each differencial caracteristics of the technical method of the coating quarts on the pratinum plated sensor. Another problem is that the caracteristics of probe sensor have an effect on the change of liquid temperature. This paper aims at clarifying of the calibrating velocity caracteristic of Hot-film probe sensor the type of V under the changing of liquid temperature.