PROBLEM TO BE SOLVED: To provide an accurate airtight testing performance method which is not affected by an amount of a filling liquid in a blood treatment instrument.SOLUTION: An airtight testing method includes the steps of: confirming that a first circuit L1, a second circuit L2, and a third circuit L3 are all kept airtight applying first pressure from a connection port PS1 of a first pressure sensor and/or a connection port PS3 of a third pressure sensor by rotating an air pump, applying second pressure by air pressuring and sucking means connected to a connection port PS2 of a second pressure sensor at the same time, and performing adjustment so that the first pressure and the second pressure P2 become the same at this time stopping pressuring and sucking by the air pump and the air pressurizing and sucking means if the first pressure and the second pressure reach substantially the same pressure and keeping the reached pressure and determining that the airtightness is kept if the reached pressure does not exceed third pressure (threshold) after keeping the reached pressure for a prescribed time.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】血液処理器内の充填液の量に影響を受けず、正確な気密試験の実施方法の提供【解決手段】第1回路L1、第2回路L2及び第3回路L3は全て気密に保たれていることを確認するステップと、エアポンプを回転させて、第1圧力センサの接続口PS1及び/又は第3圧力センサの接続口PS3から第1圧力を与え、同時に第2圧力センサの接続口PS2に接続したエアー加圧・吸引手段により第2圧力を与え、このとき第1圧力と第2圧力P2が同じになるように調節するステップと、第1圧力と第2圧力が実質的に同じ圧力に到達したらエアポンプとエアー加圧・吸引手段による加圧・吸引を止めて到達圧力を保持するステップと、所定時間放置した後、到達圧力が第3圧力(しきい値)を上回ることがなければ気密を維持していると判断するステップとを含む方法とする。【選択図】図1
