公开(公告)号：US3753092A

公开(公告)日：1973-08-14

申请号：US3753092D

申请日：1971-04-08

申请人： JOHANNA PLASTICS INC

发明人： LUDLOW T ,  CHAMPLIN K

IPC分类号： G01N27/22 ,  G01R27/26

CPC分类号： G01R27/2635 ,  G01N27/223

摘要： A self-contained apparatus for measuring small changes in the permittivity or dielectric constant of an insulating liquid such as, e.g., lubricating oil. A few drops of said liquid are placed in an open-type test cell possessing two coplanar electrodes imbedded in a low permittivity, insulating material forming its bottom surface. The electrode configuration is designed such that the electrical capacitance between electrodes is strongly dependent upon the permittivity of the liquid but is virtually independent of the quantity of liquid in the test cell. The electrodes are connected to a comparison circuit which is designed to be optimally sensitive to small changes in electrical capacitance. The comparison circuit contains a variable capacitor for balancing the capacitance of the test cell and a null meter for detecting this balance condition. The dial scale attached to the variable capacitor is initially set to zero by balancing the instrument with a standard liquid in the test cell. Measurements on sample liquids thereafter yield readings proportional to the deviation of the permittivity of the sample liquid from that of the standard liquid. In testing the quality of a lubricating oil, unused oil is employed as a standard liquid and the permittivity deviation is directly related to the amount of oxidation and other contamination present in the oil sample.

摘要翻译： 用于测量诸如润滑油的绝缘液体的介电常数或介电常数的小变化的独立装置。 将几滴所述液体放置在具有嵌入在形成其底表面的低介电常数的绝缘材料中的两个共面电极的开放式测试电池中。 电极配置被设计成使得电极之间的电容强烈地取决于液体的介电常数，但实质上与测试电池中的液体量无关。

公开(公告)号：US3616696A

公开(公告)日：1971-11-02

申请号：US3616696D

申请日：1969-08-04

申请人： JOHANNA PLASTICS

发明人： LUDLOW THOMAS B ,  SKILDUM JOHN D

IPC分类号： G01N9/10 ,  G01N31/22

CPC分类号： G01N31/221 ,  G01N9/10

摘要： BECAUSE THE CORROSIVENESS AND FREEZING POINT OF RADIATOR COOLANT ARE RELATED, THE SUITABILITY OF THE COOLANT DEPENDS ON BOTH FACTORS. TO DETERMINE THE CONDITION OF THE COOLANT IN ACCORDANCE WITH THE INVENTION THE PH AND SPECIFIC GRAVITY ARE MEASURED SIMULTANEOUSLY. THIS IN ACCOMPLISHED BY PLACING A PH MEASURING COLOR INDICATOR ON THE NOZZLE OR OTHER PORTION OF A HYDROMETER THAT IS ADAPTED TO ENTER THE SOLUTION WHEN THE HYDEOMETER IS FILLED. IN A PREFERRED FORM OF THE INVENTION INDICATOR CONSISTS OF A MATRIX COMPOSED OF A CONTINUOUS PHASE OF A MOISTURE PERMEABLE MATERIAL IN WHICH IS DISPERSED A WATER INSOLUBLE PH SENSITIVE INDICATOR.