WATER DIPPING ULTRASONIC DIMENSION MEASURING DEVICE

PURPOSE:To eliminate a measurement error due to water temperature difference and measure the outer diameter of a measurement material accurately by controlling the water temperature inside a water storage bath so that it is equal to the surface temperature of a material to be measured based on the surface temperature of the material to be measured and a flaw detection water temperature. CONSTITUTION:A material 2 to be measured which is heat-treated 1 is cooled by a cooling shower 3 and the surface temperature of the material 2 to be measured is measured by a temperature-measuring probe 4. The main body 5 of the device measures the external dimension of the passing material 2 to be measured. A water storage bath 6 supplies a flaw-detection water to the main body 5 and replenishes the hot water which is collected by a water pad 9 at the lower part of the shower 3. A controller 16 calculates the difference between the surface temperature of the material 2 to be measured which is input from the probe 4 and a hot water thermometer 11 and the flaw detection water temperature in the water bath. Then, when the detection water temperature in material 2 to be measured is higher (lower) than the flaw detection water temperature by 2 deg.C or more, a heating (cooling) command is output to a heater (cooler) 14 (15). The device 14 (15) supplies a heating (cooling) medium to a heating (cooling) coil 12 (13) according to the command and then heats (cools) the flaw detection water of the water bath 6. Therefore, even if the difference between the surface temperature of the material 2 to be measured and normal temperatures is large, an outer diameter can be measured accurately.