| 摘要 |
860,917. Electrical measuring systems. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Aug. 9, 1957 [May 14, 1956], No. 14954/56. Class 40 (1). [Also in Group XXXVI] The temperature of a liquid in a conductivity cell Cc is measured by connecting electrodes provided in the form of conductive lands round a thermometer immersed in the liquid, in an arm of the bridge shown, the thermometer and electrodes forming a capacitance, the value of which depends on the length of the mercury when under the electrode on the tube. The thermometer is connected in one arm at Cc, the other arms of the bridge consisting of a fixed resistance Rs, a fixed capacitor Cs and a variable capacitor Cv, the voltages across Cc and Cv being rectified and connected in opposition, their difference being reduced to zero by adjustment of Cv, the value of Cv for the null condition then corresponding to the temperature. The liquid is supplied from an R.F. oscillator. |
