Abstract: A reagent analyzer and method is described. In the method, a reagent card having a reagent pad is passed through an optical signal path between an optical signal source and an optical signal detector. A transition between a first electrical signal and a second electrical signal is detected to determine a substantially exact position of a leading end or a trailing end of the reagent pad. The first electrical signal is indicative of the substrate interfering with the optical signal. The second electrical signal is indicative of the substrate and reagent pad of the reagent card interfering with the optical signal. The reagent pad is moved to a known second location upon determining the substantially exact position of at least one of the leading end and the trailing end of the reagent pad. At the second location a sample is dispensed onto the reagent pad by a sample dispenser.

Abstract: A reagent analyzer and method is described. In the method, a reagent card having a reagent pad is passed through an optical signal path between an optical signal source and an optical signal detector. A transition between a first electrical signal and a second electrical signal is detected to determine a substantially exact position of a leading end or a trailing end of the reagent pad. The first electrical signal is indicative of the substrate interfering with the optical signal. The second electrical signal is indicative of the substrate and reagent pad of the reagent card interfering with the optical signal. The reagent pad is moved to a known second location upon determining the substantially exact position of at least one of the leading end and the trailing end of the reagent pad. At the second location a sample is dispensed onto the reagent pad by a sample dispenser.

Abstract: A reagent card analyzer comprises an optical signal source configured to transmit an optical signal and an optical signal detector spaced a distance from the optical signal source to define an optical signal path into which the optical signal is transmitted, the optical signal detector configured to detect the optical signal and to output an electrical signal indicative of the optical signal. A reader is configured to read a reagent pad of a reagent card. A reagent card moving mechanism is configured to move the reagent card having the reagent pad including a leading and trailing end through the optical signal path. An optical detector interface is electrically coupled with the optical signal detector and configured to receive electrical signals and to output a pad detect signal indicative of at least one of the leading and the trailing end as the reagent card is moved through the optical signal path.

Abstract: A reagent card analyzer comprises an optical signal source configured to transmit an optical signal and an optical signal detector spaced a distance from the optical signal source to define an optical signal path into which the optical signal is transmitted, the optical signal detector configured to detect the optical signal and to output an electrical signal indicative of the optical signal. A reader is configured to read a reagent pad of a reagent card. A reagent card moving mechanism is configured to move the reagent card having the reagent pad including a leading and trailing end through the optical signal path. An optical detector interface is electrically coupled with the optical signal detector and configured to receive electrical signals and to output a pad detect signal indicative of at least one of the leading and the trailing end as the reagent card is moved through the optical signal path.

Abstract: The service life of amperometric electrochemical oxygen sensors is increased by operating the electrodes of such sensors at a polarization voltage suitable for measuring the oxygen content of samples only during calibration or when measuring such samples and thereafter modulating the polarization voltage to a lower voltage such that substantially no electrical current is produced by the electrodes.

Abstract: The service life of amperometric electrochemical oxygen sensors is increased by operating the electrodes of such sensors at a polarization voltage suitable for measuring the oxygen content of samples only during calibration or when measuring such samples and thereafter modulating the polarization voltage to a lower voltage such that substantially no electrical current is produced by the electrodes.

Abstract: Method and apparatus for sensing fluid interface(s) in a complex fluid such as centrifuged blood, includes a sensing assembly with a microwave source and a microwave sensor positioned in spaced opposed relation, the microwave source and sensor defining a microwave propagation path. Relative motion is induced between the sample container and the microwave energy propagation path in the region between the source and sensor in a direction that intersects and is essentially perpendicular to the microwave energy propagation path; and processor apparatus responsive to the scanning apparatus and the modification in microwave energy sensed by the microwave sensor provides an indication(s) of the location(s) of a fluid interface(s) in the container.

Abstract: An analysis system for analyzing a biological fluid or the like for a constituent of the interest includes metal body structure with sample flow path channel structure that serially interconnects heater chamber structure, recess structure for receiving a reaction chamber cartridge and an analysis region to which a measuring system is coupled. The reaction chamber cartridge preferably includes reaction chamber structure with an immobilized enzyme in the reaction chamber that is capable of converting the constituent of interest to a constituent detectable by the measuring system. Cooperating with the metal body structure is a transparent face plate structure which permits visual observation of the sample flow path in the metal body structure.

Abstract: A pressure monitoring system for use with an electrofluidic device for sensing pressure includes a pump for supplying fluid to the electrofluidic sensing device. An electrical switching circuit controls the supply of fluid to the sensing device and is responsive to the external pressure level applied to the sensing device; this circuit also cyclically causes the supplied pressure to vent when the pressure of supplied fluid inside the sensing device is substantially equal to the applied external pressure, and then start the fluid supply to the device over again. This system further includes a measuring element for detecting the pressure level of the supplied fluid, and a digital meter for displaying the analogous detected pressure level during supply of the fluid.