PROBLEM TO BE SOLVED: To provide a transducer protection filter in which a membrane member can be held at an adequate holding force, and the sealing of the membrane member is adequately maintained while the membrane member is protected from being damaged.SOLUTION: A transducer protection filter comprises: a first housing member 6a a second housing member 6b a hydrophobic membrane member 6c and a first holding surface 6ab and a second holding 6bb which contact outer peripheral edges of the membrane member 6c to hold the membrane member 6c. In the transducer protection filter, a holding portion α has an adequate holding range A in which a separation dimension between the first holding surface 6ab and the second holding surface 6bb is set adequately, a first holding range B in which the separation dimension is set larger than the adequate holding range A, and a second holding range C in which the separation dimension is set smaller than the adequate holding range A. In addition, the holding ranges are set such that the adequate holding range A is interposed between the first holding range B and the second holding range C continuously in a radial direction of the membrane member 6c.COPYRIGHT: (C)2015,JPO&INPIT【課題】膜部材を適正な挟持力にて挟持させることができ、膜部材のシールを十分に維持させつつ破損を防止することができるトランスデューサ保護フィルタを提供する。【解決手段】第1ハウジング部材6aと、第2ハウジング部材6bと、疎水性の膜部材6cと、膜部材6cの外周縁部に当接して挟持する第1挟持面6ab及び第2挟持面6bbとを具備したトランスデューサ保護フィルタにおいて、挟持部αは、第1挟持面6ab及び第2挟持面6bbの間の離間寸法が適正に設定された適正挟持範囲Aと、適正挟持範囲Aより当該離間寸法が大きく設定された第1挟持範囲Bと、適正挟持範囲Aより離間寸法が小さく設定された第2挟持範囲Cとを有するとともに、適正挟持範囲Aを挟んで第1挟持範囲B及び第2挟持範囲Cが膜部材6cの径方向に対して連続的に設定されたものである。【選択図】図5
