Oxygen concentration probe

Electrochemical cells where ions dissipate through a solid electrolyte are mainly used for measuring oxygen concentrations. The most common sensors based on this principle are the A-probe for monitoring combustion engines in motor vehi-... 

Potentiometric lambda-probes are not suitable for measuring the oxygen concentration at 1 3> 1. 

Supernatant BOD5 was measured by the standard method of the American Public Health Association (24), but using the EIL dissolved oxygen probe model no. 8012 to measure oxygen concentration (Electronic Instruments Ltd., Richmond, Surrey, UK.)... 

Two different kinetic approaches have been used to obtain mechanistic information [15,16]. Kinetic studies carried out by EPR spectroscopy using fusinite as a paramagnetic probe of the oxygen concentration allowed the oxidizability of poly(hydrosilane)s to be obtained [15]. Oxidizability values of 1.8 x 10 and... 

Variation of lateral mobility (fluidity) and polarity gradient have been reasonably established in certain calcium alkarylsulfonate micelles using 1-pyrene carboxylic acid probes with varying alkyl chain lengths. The existence of a polarity gradient in an inverted micelle may be responsible for the creation of an oxygen concentration gradient. 

A kinetic study of the photosensitized oxidation of tryptophan-alkyl esters in Triton X-100 micellar solutions has been carried out by Criado et al. [24], The results obtained are presented in Table 6. These data show an important decrease in the relevance of the photo-oxidative pathway in the esterified compounds in the presence of the micelles. The magnitude of the effect seems to be extremely sensitive to the location of the probe, increasing as the length of the ester hydrocarbon chain increases. These results are interpreted in terms of the competition between the local oxygen concentration and the solvent micropolarity effect that... 

In all of these tests, the specimens, 75 mm square and up to 25 mm thick, are exposed to radiant heat with and without a pilot flame(s). Decomposition takes place inside a closed cabinet of 0.51 m3. There is no control of the air flow or oxygen concentration through the fire zone and the effluent is mixed by natural convection, as it accumulates within the closed cabinet. Gases are sampled using probes mounted in the center of the cabinet. 

The fluorescence lifetime and polarization of an extrinsic probe bound tightly to a spherical protein have been measured at different oxygen concentrations. The following data are obtained ... 

The method is usually adopted when the transferring component is 02, since it is possible to monitor the dissolved oxygen concentration with a polarographic electrode(Clark cell). The method requires some precautions. The probe has an intrinsic time constant tp (the time needed to attain 63% of the reading after a stepwise concentration change) so that its output is not directly related to the actual concentration, especially when the concentration in the liquid phase changes rapidly. Indeed the measurement may be... 

Lambda probe — The so-called lambda probe (lambda sensor) is a potentiometric oxygen - gas sensor that is used to monitor the partial pressure of oxygen po2 (oxygen concentration), e.g., in the exhaust gas of cars in order to control the air/fuel ratio that is going to the internal combustion engine. The term lambda originates from the stoichiometry number A which describes the composition of the air/fuel mixture, as follows ... 

Oxygen sensors — Device for measurement of oxygen concentration or activity. See - Clark cell, - lambda-probe. 

Atomic oxygen concentrations may be determined by the calorimetric method if the surface of the catalytic probe is chosen suitably. Linnett et have... 

Absolute atomic oxygen concentrations are best measured with the isothermal resistance probe. Elias et describe investigations of atomic oxygen reactions using a silver coated platinum wire coil. 

Melanins have photoprotective properties. Paramagnetic changes occur upon ultraviolet or visible irradiation and have been studied by ESR. Two types of reactions have been identified [161] production of melanin free radicals and reduction of oxygen to O2. Oxygen consumption in the polymer solution is strongly wavelength dependent, as shown by spin-probe measurements of oxygen concentration [167],... 

The physiological oxygen concentrations in arterial blood, 0.15 mmol/1, and venous blood, 0.01 mmol/1, are much lower than that of glucose (5-15 mmol/1). Continuous flow-through blood glucose sensors based on oxygen probes therefore exhibit a nonlinear current-concentration dependence (Layne et al., 1976). 

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