Odor detection device that detects minute amounts of musty odor substances, etc.

摘要

PROBLEM TO BE SOLVED: The water quality standard value of 2-methylisoborneol (2-MIB) is 10ppt (10ng / L) in the Waterworks Law, and 2-MIB of tap water is detected using a Sn02 (tin oxide) semiconductor sensor element There is no paper or knowledge. In addition, some residents may complain with a small amount of musty odor that is lower than the setting value of 3ppt to 5ppt (3ng to 5ng) of water supply in 2-MIB. However, in the river surface water, lake water, groundwater and dam water, which are raw water sources, trace amounts of 3 ppt to 5 ppt (3 ng to 5 ng) of 2-MIB are strong when other odors are strong. There is a problem that other odors are detected in a state where they are buried. A water receiving tank 71 to which raw water 70 is supplied through a water supply pipe 72, a drain tank 61 disposed at a position lower than the water receiving tank 71 to make a drop, and an inner bottom of the drain tank 61 are disposed. A water detection tank 81 whose upper surface is opened, a shut-off tank 62 which is arranged at the upper end in the drainage tank 61 and whose lower surface opening covers the upper surface opening of the water detection tank 81, and whose opening is upward on the upper surface of the drainage tank 61 An odor cylinder 100 in which a sensor unit 105 having a semiconductor sensor element 106 disposed therein is accommodated, an odor pipe 101 in which a lower surface opening portion is disposed in a ceiling portion of the shut-off tank 62 toward the water detection tank 81, and a water receiving tank 71 includes a test water pipe 82 for supplying raw water in 71 into the odor pipe 101 by a head, and a blower 92 for sending air into the water test tank 81 via an air pipe 94 as main components. Cylinder 10 The semiconductor sensor element 106 of the sensor unit 105 is attached to the upper surface of the partition plate 108 that divides the interior of the zero up and down, and is exposed in the odor chamber 100a below the odor cylinder 100 partitioned by the partition plate 108. In the chamber 100a, an odor cap 102 communicating with the odor cylinder 100 is provided, and a plurality of odor holes 103 are provided on a peripheral edge of the odor cap 102, and a part of the partition plate 108 is provided with the odor cylinder 100. Ventilation holes that lead to the upper exhaust chamber 100b are provided. [Selection] Figure 1