| 摘要 |
628,840. Determining physical qualities and dimensions of materials. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., and FAGAN, C. P. Dec. 30, 1946, No. 38056. [Class 37] An electrode structure for directly determining the pH content of agricultural soil comprises a central electrode 5 composed, e.g., of 97 per cent antimony and 3 per cent lead. This electrode is mounted in a stainless steel container 1 from which it projects as -shown at 5a and is surrounded by polythene insulation 8. The end of this container is closed with sintered glass 4, held in place by clips 3 formed of the end of the container. A rubber ring 9 surrounding the edge of the glass protects it from shock. The annular space 10 between the insulation 8 and the stainless steel container is filled with electrolyte such as saturated potassium chloride. The electrode is screwed to a copper bar 6 to which connection is made by a heavily-insulated flexible conductor 7, This conductor, together with a flexible insulating tube 11 passes through a flexible copper tube 2 to an instrument box containing a reference 13 and an electrometer measuring apparatus. A folding aluminium stand may be provided to hold this box above the soil while the operator manipulates the electrode structure. |
