| 摘要 |
PURPOSE:To perform measurement on the basis of the change in properties without using expensive machinery or a power source, by immersing a rubber piece, of which the properties are preliminarily measured, in fuel containing alcohol for a predetermined time before measuring the properties of the immersed rubber piece. CONSTITUTION:Fuel comprising methanol-containing hydrocarbon being a specimen 6 is put in a container 1 so as to reach a mark line 4 and a test piece 5 is suspended from a lid 3 to be immersed in the fuel for a predetermined time. The temp. of the specimen 6 is measured by a thermometer 7. The test piece 5 to be measured is taken out and the hardness thereof is measured by a rubber hardness meter. The hardness after immersion is compared with a calibration curve preliminarily fabricated by using a specimen prepared by mixing gasoline and methanol to perform the measurement of methal concn. As the test piece, a high nitrile NBR rubber vulcanized sheet, of which the initial hardness HR is 73 and tensile strength is 180kgf/cm<2>, is used. |
