| 摘要 |
729,575. pH Electrodes. JACKSON, J. Dec. 3, 1953 [Sept. 3, 1952], No. 22200/52. Class 37. A reference electrode for use in pH measurements comprises a glass electrode chamber 2 containing, at its lower end, mercury 3 and mercury-calomel paste 4 separated by a constriction 5, and held in position by an asbestos plug 4A, the bottom of the chamber 2 being closed by a porous ceramic rod 7 providing a leakway. The electrode chamber is supported in a bridge solution container 13 completely filled with potassium chloride solution 18 .and excess potassium chloride 19, the top of the container 13 being sealed by a bung 11 and cap 14, and the bottom of the container being closed by a porous ceramic plug 17, providing a passageway between the bridge solution 18 and the liquid to be tested, which would allow fluid flow at a rate of 0.02 to 2.0 mls. per hour under a head of one foot of water. The container 13 may have a stoppered filling- branch, and the porous plug 7 may alternatively be a small bundle of asbestos fibre. |
