| 摘要 |
<p>856,087. Spectrometer cells. NATIONAL RESEARCH COUNCIL. May 25, 1959 [June 3, 1958], No. 17765/59. Class 97(1) A cell for containing samples of liquid for infra-red spectroscopic analysis is made as a unitary body from a single piece of material. For preference, rock salt is used, but other materials which are transparent to infra-red radiation may also be used; for example, the halides of the alkali-metals, silver, barium calcium and lead, and also arsenic-trisulphide. If the cell is made from rock salt, a single crystal must be used of sufficient size to allow the cell to have dimensions of the order of 2cm x lcm x 0.5cm. The cell cavity is formed by ultrasonic impact drilling and is normally rectangular in shape with planar parallel faces as shown in Fig. 1. The uppermost portion of the cavity is first drilled by conventional means to form a circular aperture for a stopper. If it is desirable to have a small opening in order to minimize evaporation, this is drilled in a separate piece of rock salt which is then bonded to the top of the cell by moistening with aqueous sodium chloride and clamping under pressure at a temperature of 110‹C for 12 hours. To obtain a very thin cavity without deformation of the grinding tool, the tool is reinforced with cylindrical bars on both sideedges. The resulting cavity will then have a dumb-bell shaped cross-section as in Fig. 8 in the central parallel-sided portion of which the test liquid is held by capillary action without the cylindrical portions having to be filled.</p> |
