Abstract: A solid electrolyte dual gas sensor 10 is made, containing a container body of a first solid electrolyte 11, in contact with a monitor electrode 17 exposed to a monitored gas environment 13 containing selected gas components to be measured, and in contact with a reference electrode 15 which is additionally isolated from the monitored gas environment by a second solid electrolyte 16, and optionally 14, where the second solid electrolyte, at the operating temperature of the gas sensor, is effective to dissociate to provide the sole source of self-generated gases at the reference electrode 15, corresponding to the selected gas components to be measured in the monitored gas environment, where, at the operating temperature of the sensor, the first solid electrolyte 11 is effective to conduct oxygen ions, and the second solid electrolyte 16 is effective to conduct ions selected from the group of sodium ions, potassium ions, and their mixtures.

Abstract: A closed tonometer for subcutaneous insertion is disclosed having a small closed equilibrating bath. Three noble metal electrodes, preferably platinum (Pt), communicate through electrical conductors to the bath at spacings exceeding 0.2 mm. Each noble metal electrode is typically exposed to the bath by embedding the noble metal in a dielectric and cutting both dielectric and electrode so that the exposed electrode is flush with and a part of the closed bath wall. The bath is contained within an oxygen permeable membrane -- preferably Silastic.RTM. a registered trademark of Dow Corning Corporation of Midland, Michigan. The bath contains a sodium chloride (NaCl) solution, preferably 0.9%, and small amounts of a hydroquinone such as a tenth of a gram of pure ascorbic acid per 30 ml of NaCl solution. One of the noble metal electrodes becomes a quinhydrone reference electrode preserving a precise voltage differential with respect to the electrolyte bath.

Abstract: An across-the-stack gas analyzing spectrometer has a radiation source assembly including a cylindrical tube 22 having, in succession from its outer end toward the stack end a radiation emission assembly 28, a first lens assembly 30, and an AOTF assembly, all in optically aligned arrangement because of the circular perimeter of the elements in the circular tube, the arrangement also including a projecting second lens nozzle 98 received in an air window assembly 104 which forms a venturi with the second lens, the air window having a ball joint arrangement 120 for easy alignment of the directed beam, and also including a small diameter air window tube 142 through which clean air is directed into the stack through a larger diameter stack opening.

Abstract: A detector assembly of a spectrometer device which includes a built-in test gas chamber, has a housing defining a chamber with a first end having a first aperture and a second end having a second aperture opposite the first aperture. While light transmissive windows can be mounted in the opposed apertures to enclose the chamber, it is preferred that a focusing lens be mounted in the first aperture and a detector in the second aperture in order to enclose the housing ends and define the chamber. The chamber has a cone-like inner surface tapering from the first aperture to the second aperture. The housing has a test gas inlet in communication with the chamber and disposed proximate the first end thereof. A test gas outlet is in communication with the chamber and disposed proximate the second end. The test gas inlet is so oriented as to introduce test gas into the chamber on a tangent to the first end, first aperture resulting in a tangential flow path direction within the cone-like chamber.

Abstract: The invention provides both preferred material alloys and electrode lead wire configurations for electrically connecting the solid electrolyte cell in a gas sensing probe to a remote measuring circuit.

Abstract: In a gas measuring probe assembly having a gas sensing device located within a tubular housing positioned within a gas environment to be monitored, a tubular calibration gas flow pattern is established within the tubular housing substantially parallel to the walls of the tubular housing to sweep the monitored gas environment from the tubular housing and expose the gas sensing device to a calibration gas mixture substantially free of the monitored gas environment. This technique permits the in situ calibration of gas detectors, and is especially useful in calibrating stack gas monitoring probes.

Abstract: In a gas measuring probe assembly having a gas sensing device within a tubular housing positioned within a gas environment to be monitored, a tubular calibration gas flow pattern is established within the tubular housing substantially parallel to the walls of the tubular housing to sweep the monitored gas environment from the tubular housing and expose the gas sensing device to a calibration gas mixture substantially free of the monitored gas environment. This technique permits the in situ calibration of gas detectors, and is especially useful in calibrating stack gas monitoring probes.