Nippon Telegraph and Telephone Corporation

Ntt Advanced Technology Corporation

Hl.i, Incorporated

Yasuko Maruo

Tohru Tanaka

Shigeo Ogawa

Jiro Nakamura

Seizou Sakata

Tatsuya Kunioka

Takashi Miwa

Toshiaki Tamamura

Shigekuni Sasaki

Shinji Ando

Fumio Yamamoto

Tohru Matsuura

Shinsuke Matsui

Takashi Ohyama

Takayoshi Hayashi

Shiro Matsumoto

Seizo Sakata

Makoto Tarumi

Shigekazu Uematsu

Mark A Fitchett

A vessel () containing a detector solution () is prepared. The detector solution () is an aqueous solution prepared by dissolving a detector component containing a dye which changes its color when reacting with ozone gas, a humectant, and an ultraviolet absorber having a hydrophilic group. A prepared sheet-like carrier () is dipped in the detector solution () for, e.g., 30 sec, thereby forming an impregnated sheet () by impregnating the sheet-like carrier () with the detector solution (). The impregnated sheet () is then dried by evaporating the solvent (medium) such as water contained in the impregnated sheet (), thereby forming a sheet-like ozone detecting device ().

Ozone detecting device

An aqueous solution is formed by dissolving a dye made of alizarin and a humectant made of glycerin, and alkalized by dissolving a base (alkaline substance), thereby preparing a detector solution () in which the content of the humectant is about 20 wt %. An impregnated carrier () impregnated with the detector solution () is formed by dipping for 30 sec a sheet-like carrier () made of cellulose filter paper in the detector solution () so that the carrier () is impregnated with the detector solution (). The impregnated carrier () is pulled up from the detector solution (), and dried in dry nitrogen by evaporating a solvent such as water contained in the impregnated carrier (), thereby forming an ozone detecting device ().

A sensing element in which a dye that changes in the light absorption characteristic of the visible region upon reaction with ozone gas is deposited in the pores of a porous material is prepared. A change in dye before and after exposing the sensing element to a measurement environment for a predetermined time is measured. The ozone gas amount in measurement target air is measured on the basis of the change in dye.

Ozone gas sensing element, detection apparatus, and measurement method

Ozone gas measurement apparatus

Detection card

In this invention, a mixture of a diazotizing reagent which reacts with nitrous ions to produce a diazo compound, a coupling reagent which couples with a diazo compound to produce an azo dye, and an acid is placed in pores of a transparent porous body to prepare a sensor element. Nitrogen dioxide gas is sensed in accordance with a color change before and after the sensor element is exposed to air to be measured for a predetermined time.

Nitrogen dioxide gas sensing method, nitrogen dioxide gas sensor element, and nitrogen dioxide gas sensor using the same

A polyimide optical waveguide comprising a core made of polyimide whose refractive index is controlled to a predetermined value by electron beam irradiation, and a cladding set in contact with the core and having a refractive index lower than that of the core.

Polyimide optical waveguide and method of manufacturing the same

Polimide optical waveguide

Growing community of inventors

Kanagawa, Japan

Yasuko Maruo