Abstract:
1353956 Electro-chemical analysis BECKMAN INSTRUMENTS Inc 16 Sept 1971 [2 Oct 1970] 43162/71 Heading G1N The invention relates to an electro-chemical cell having a membrane type reference electrode, for measuring the pH of aqueous solutions containing organic liquids e.g. benzene which tend to form an insulating layer on the permeable membrane. To prevent this a SURFACTANT is added to the sample solution and/or the internal electrolyte of the reference electrode. Non-ionic or anionic surfactants are preferred. Cationic surfactants have been found unsatisfactory in that they tend to increase pH readings. Ethoxylates of isomeric linear alcohols, and alkyphenyl ethers of polyethylene glycol have been used. Examples are given. The membrane may be P. T. F. E., polyethylene or P.V.C.
Abstract:
1353956 Electro-chemical analysis BECKMAN INSTRUMENTS Inc 16 Sept 1971 [2 Oct 1970] 43162/71 Heading G1N The invention relates to an electro-chemical cell having a membrane type reference electrode, for measuring the pH of aqueous solutions containing organic liquids e.g. benzene which tend to form an insulating layer on the permeable membrane. To prevent this a SURFACTANT is added to the sample solution and/or the internal electrolyte of the reference electrode. Non-ionic or anionic surfactants are preferred. Cationic surfactants have been found unsatisfactory in that they tend to increase pH readings. Ethoxylates of isomeric linear alcohols, and alkyphenyl ethers of polyethylene glycol have been used. Examples are given. The membrane may be P. T. F. E., polyethylene or P.V.C.
Abstract:
THE DISCLOSURE RELATES TO AN IMPROVEMENT IN AN ELECTROCHEMICAL CELL FOR USE IN ION POTENTIAL MEASUREMENTS OF SOLUTIONS THE CELL CONTAINS A SENSING ELECTRODE, A REFERENCE ELECTRODE, AND AN EXTERNAL ELECTROLYTE COMPRISING THE SOLUTION TO BE TESTED. AT LEAST ONE ELECTRODE COMPRISES AN INTERNAL HALF CELLS SUPPORTED IN A CONTAINER OF NONCONDUCTIVE MATERIAL CONTAINING A SALT SOLTUION, AN INTERNAL ELECTROLYTE AND A LIQUID JUNCTION STRUCTURE OF AN ION PERMEABLE MATERIAL. THE IMPROVEMENT COMPRISES A SURFACTANT ADDED TO THE CELL SO THAT THE CONTACT ANGLE BETWEEN THE SOLUTION AND THE LIQUID JUNCTION STRUCTURE IS LESS THAN ABOUT 90*. AS A RESULT THE LIQUID JUNCTION STRUCTURE IS MADE MORE PERMEBLE TO WATER MOLECULES. AN IMPROVED ELECTROCHEMICAL ELECTRODE FOR USE IN ION POTENIAL MEASUREMENTS OF SOLUTIONS IS ALSO DISCLOSED.
Abstract:
A bypass filter assembly and method of obtaining a filtered sample from a process stream or the like in which the process stream is introduced into a filter chamber so as to produce a symmetrical bifurcated flow pattern of fluid therein which promotes a counter-rotating scouring or cleaning action on the membrane filter in the chamber. The housing of the assembly is divided into two sections. The inlet and outlet ports for the process stream and the filtered sample port are all located in one section of the housing so that the other section, namely the filter cap, may be removed from the first section without disconnecting any flow lines from the cap, thus facilitating rapid removal of the cap and replacement of the filter element therein.
Abstract:
A bypass filter assembly and method of obtaining a filtered sample from a process stream or the like in which the process stream is introduced into a filter chamber so as to produce a symmetrical bifurcated flow pattern of fluid therein which promotes a counter-rotating scouring or cleaning action on the membrane filter in the chamber. The housing of the assembly is divided into two sections. The inlet and outlet ports for the process stream and the filtered sample port are all located in one section of the housing so that the other section, namely the filter cap, may be removed from the first section without disconnecting any flow lines from the cap, thus facilitating rapid removal of the cap and replacement of the filter element therein.
Abstract:
A temperature sensing circuit generates a voltage proportional to the difference between a controlled temperature and a predetermined reference temperature. The voltage is integrated in an integrating amplifier whereby average temperature offset error is reduced to zero. The integrated voltage is compared to a reference potential in a comparator to generate a control signal when the integrated voltage exceeds the reference potential. The control signal operates a switching device through which electrical power is conducted to a heater whereby the controlled temperature is established.
Abstract:
An improved catalytic reactor system and method for removing interferents such as reactive hydrocarbons from the gas being sampled by gas component determination apparatus is disclosed. The sample from which the interferents are to be removed is blended with ozonized air and saturated to at least 15% with water vapor. The mixture is then passed through the catalytic reactor which, preferably, contains a mixture of platinum oxide mixed with and and maintained at an operating temperature of 200 to 280.degree.C. Additional catalytic mixtures which may be employed in the reactor are also disclosed. Methods of preventing the poisoning of catalytic reactors and rejuvenating poisoned catalytic reactors are also disclosed.
Abstract:
In apparatus for analyzing the exhaust gas of a motor vehicle, the apparatus including an oxygen sensor and means for sampling a portion of the exhaust gas and conducting the sample to the sensor, there is disclosed an improvement wherein the exhaust gas is used to heat a moisture barrier and the oxygen sensor and is then cooled before being directed through the moisture barrier to the sensitive area of the oxygen sensor. This arrangement prevents moisture form condensing on the sensitive area of the oxygen sensor, which moisture would interfere with the operation of the sensor.