Gas indicator and gas sensor sheet

摘要

A gas indicator, which can be used over a broad range of gas concentration from a low concentration gas to a high concentration gas, includes a substrate sheet and plural change-color layers formed from a gas sensor ink on said substrate. The plural change-color layers are formed parallel to each other in a stripe pattern. The gas sensor ink contains an anthraquinone dye having at least one of a primary amino group or a secondary amino group.