Patent ID: 8295718
Filing Date: 2012-10-23
Classification: G01N,G03B,G03G

Abstract:
1. A concentration detection apparatus comprising: a light-emitting element that emits light; a light-emitting-element holding section that holds the light-emitting element; a light-receiving element that receives light emitted from the light-emitting element; a light-receiving-element holding section that holds the light-receiving element and is provided opposite to the light-emitting-element holding section with a gap therebetween; a moving section that can move through or at the gap between the light-emitting-element holding section and the light-receiving-element holding section; and a gap adjusting section that adjusts a value of the gap as a distance between the light-emitting-element holding section and the light-receiving-element holding section, wherein the gap adjusting section includes a spacer that is provided between the light-emitting-element holding section and the light-receiving-element holding section and further includes a joining section that joins the light-emitting-element holding section and the light-receiving-element holding section with the spacer being provided therebetween.