PROBLEM TO BE SOLVED: To provide a liquid agent dilution device capable of performing stable dilution use of a liquid agent with a high dilution rate.SOLUTION: A liquid agent dilution device has a main flow passage 8 making a solvent pass. The main flow passage 8 branches into a first system 9 and a second system 10, and they newly join each other downstream. The liquid agent dilution device is provided with an ejector pump part communicating with a supply source of a liquid agent and sucking the liquid agent into the solvent by a negative pressure in the middle of the first system 9, the second system 10 joins the first system 9 downstream of the ejector pump part not through the ejector pump part, and the liquid agent dilution device is provided with a changeover device 27 changing over between dilution water discharge in which the solvent passes both the first system 9 and the second system 10, and raw water discharge in which the solvent passes only the second system 10, and reduces a minimum cross section inside a flow passage of the second system 10 when discharging dilution water compared to when discharging raw water.COPYRIGHT: (C)2015,JPO&INPIT【課題】高希釈倍率で安定した液剤の希釈使用をすることができる液剤希釈装置を提供する。【解決手段】溶媒を通過させる主流路8を有し、この主流路8は第一系統9と第二系統10とに分岐するとともに下流で再び合流してなり、第一系統9の途中に、液剤の供給源と連通して負圧により液剤を溶媒に吸引するエジェクターポンプ部を設け、第二系統10はエジェクターポンプ部を経由せずに、エジェクターポンプ部の下流で第一系統9と合流し、かつ、上記溶媒が第一系統9および第二系統10の両方を通過する希釈水吐出と、上記溶媒が第二系統10のみを通過する原水吐出とを切り替える切替装置27を設け、上記希釈水吐出時には、上記原水吐出時よりも第二系統10の流路中の最小断面積を小さくする。【選択図】図3
