| 摘要 |
PCT No. PCT/SE97/00464 Sec. 371 Date Sep. 17, 1998 Sec. 102(e) Date Sep. 17, 1998 PCT Filed Mar. 20, 1997 PCT Pub. No. WO97/35175 PCT Pub. Date Sep. 25, 1997The present invention relates to a device for measuring density or determining the presence and the amount of materials of different density in an object to be measured, of a solid, liquid or gaseous material, said device comprising at least one source of radiation for emitting electromagnetic radiation, and at least one sensor for measuring the radiation intensity, so positioned as to absorb radiation form the source of radiation and being connected to a calculation unit. In accordance with the invention the device emits radiation of at least two wavelenghts and comprises measurement means for determination of the extension of the object between the source of radiation and the sensor. In addition, the invention relates to a method of measuring density, comprising radiating electromagnetic rays through an object to be measured and measuring the radiation intensity on the ray-exit side of the object to be measured. In accordance with the method the extension of the object is measured along the path of the radiation through the object to be measured and the radiation is effected at least at two different wavelenghts. |
