TEST TUBULE HAVING INDICATOR FOR DETECTION SUBSTANCE BY COLORIMETRY

摘要

PURPOSE: To prevent the quality of a small testing tube for detecting dissolved gas from decreasing by closing the opening of the small testing tube filled with an indicator with a transmission hydrophobic film for a detection substance and sealing the hydrophobic film with a covering that is soluble to a liquid to be tested. CONSTITUTION: An indicator 3 is filled into a small tube body 2 of a small testing tube 1 and the indicator 3 is retained by an airtight closure 4 and a porous plug 5. An indication mark 6 is written on the small tube body 2 and an opening 7 of the small testing tube 1 is covered with a transmission film 8 for a substance to be detected and the surface of the film 8 is sealed by a covering 9 that is soluble to a liquid to be inspected. An airtight air room 10 is provided at an edge part that is opposite to the opening 7 of the small tube body 2. When the small testing tube is dipped in the liquid to be tested, the covering 9 is dissolved and a gas to be detected passes through the film 8 and the porous plug 5 and penetrates through the indicator 3, thus discoloring the indicator 3. As a result, the covering 9 can prevent a harmful substance from entering the indicator of the small testing tube 1 other than at the time of use.