LEVEL METER, MOLD DEVICE, AND METHOD FOR OPERATING MOLD DEVICE

To accurately measure a liquid surface over 400 mm from the bottom of a casting mold to the liquid surface when measuring the liquid surface level of high-temperature liquid such as molten steel.SOLUTION: A level meter 1 comprises: a cylindrical guide pipe 10 that is disposed in parallel to a liquid surface 101 of high-temperature liquid 100 and propagates microwaves or millimeter waves in its internal space; an antenna 20 that is disposed opposite to one opening 10a of the guide pipe 10; transmission and reception means 30 for microwaves or millimeter waves that is connected with the antenna 20; and a reflecting plate 40 that is disposed opposite to the other opening 10b of the guide pipe 10, reflects the microwaves or millimeter waves transmitted from the antenna 20 toward the high-temperature liquid 100, and guides the reflected microwaves or reflected millimeter waves to the guide pipe 10. The pipe length L of the guide pipe 10 is adjusted to a length at which phase constants in a TE mode and a TM mode of the microwaves or millimeter waves match each other.SELECTED DRAWING: Figure 1 【課題】溶鋼等の高温液体の液面レベルを測定する際に、鋳型の底から液面までの高さ約４００ｍｍに渡って精度良く液面を計測する。【解決手段】レベル計１は、高温液体１００の液面１０１と平行に配設され、その内部空間にマイクロ波またはミリ波を伝搬させる筒状のガイドパイプ１０と、ガイドパイプ１０の一方の開口１０ａに対向して配設されるアンテナ２０と、アンテナ２０に接続するマイクロ波またはミリ波の送受信手段３０と、ガイドパイプ１０の他方の開口１０ｂに対向して配設され、アンテナ２０から送信されたマイクロ波またはミリ波を高温液体１００に向けて反射させるとともに、反射マイクロ波または反射ミリ波をガイドパイプ１０に導くための反射板４０を備えるとともに、ガイドパイプ１０のパイプ長Ｌをマイクロ波またはミリ波のＴＥモードとＴＭモードとの位相定数が一致する長さにする。【選択図】図１