| abstract |
An optical sensor apparatus for detecting a vapor of an organic solvent is characterized by a simple structure which allows easy manufacture, high reliability, low cost, compactness in size, and portability. The optical sensor apparatus has a light source unit which emits light for irradiating a polymer thin film formed on a flat reflecting substrate of a sensing element. Light reflected by the sensing element is detected by a light detecting unit. The light source unit, the sensing element, and the light detecting unit are integrally supported by a housing. The polymer thin film which comes into contact with a vapor of an organic solvent causes a change in the thickness and a reflective index thereof. This change is utilized to detect the existence and/or concentration of a vapor of an organic solvent. |