| 摘要 |
<p>A method and device for measurement of concentrations of solutions using deflection of an ion exchange membrane in an alternating electrical field are designed for economical construction, high sensitivity, and durability. The ions on the membrane (11), which is placed in the solution, form a hydration envelope in opposition to the solution. Water is exchanged between membrane and solution until an osmotic pressure difference causes a pressure balance condition. The position of the membrane is a measure of the concentration of the solution. The membrane (11) is supported in the solution by a spring (12) and passes through a slit in a cylinder (17) containing three electrodes (14, 15, 16) two of which produce an alternating electric field whose strength the other detects. Positional changes of the membrane caused by concentration variation cause a non-conducting plate (13) to move in the field, thus affecting the detected field strength.</p> |
