Abstract: Photometer with at least one measuring beam traversing a space that contains measuring gas is improved by a solid state detector made of a foil which is specifically made of polyvinyl-idene-fluoride or polyvinyl-fluoride or polyvinyl-chloride, and having an area, being at least as large as the cross-sectional area of the radiation that leaves the measuring and gas containing chamber; a measuring signal is extracted from the foil. The foil is preferably blackened and has a thickness between 6-10 micrometers.

Abstract: An infrared photometer having a measuring cuvette with entrance and exit windows and an output detector preferably made of polyvinylidenfluoride; a second infrared detector definitely made of polyvinylidenfluoride, being partially transmissive is disposed in front of the entrance window of the cuvette, and a selecting cuvette is insertible in front of this second detector.

Abstract: A infrared gas analyzer having measuring and reference chambers and receiving chambers respectively disposed on radiation exit sides of the measuring and reference chambers and being filled with a particular gas; a pressure communicating duct system including a particular chamber interconnects the two receiving chambers is partitioned by a foil of polyvinylidenfluoride being piezo electrically effective to generate an electrical signal on account of a pressure differential between the two receiving chambers, as indication of the concentration of the measuring gas, i.e., host gas that flows through the measuring chamber.

Abstract: A photometer includes a radiation source, a measuring chamber and a receiver, all arranged in a casing and through coupling-decoupling members definite temperature gradients are produced between the measuring chamber and the receiver-transmitter and other gradients through appropriate coupling members are established towards the cooled housing.

Abstract: A nondispersive, two-beam, infrared gas analyzer with two differently long measuring gas cells and differential detectors is improved by gilt detection cell interiors and absorbing rods in the detector cell which is in line with the shorter measuring gas cell. Adjustable absorption permits suppression of cross sensitivity errors.

Abstract: The chopped infrared radiation leaving a measuring and sample gas chamber in an infrared gas analyzer is passed through and into two serially arranged detection chambers which are connected to a differential pressure chamber with capacitive pickup. The chambers are filled with gas of the type whose concentration, in the sample gas, is to be detected. One of the detector chambers contains a thin black wire, a diaphragm on the outside may shield an adjustable portion of that wire from radiation. The wire absorbs all radiation it intercepts and heats the environment.

Abstract: A two-beam, infrared gas analyzer includes a front and a rear detection cell in each path filled with gas of the type to be detected; and a pressure-differential chamber with capacitor pick-up is connected to these front and rear cells. The rear cells are constructed to ensure substantially complete absorption of all radiation of the absorption band being characteristic of the component to be detected. In one example, filters are interposed between front and rear cells for broadband, i.e., nonselective attenuation. Alternatively, the rear cells are connected to a reservoir of the same gas to attenuate pressure variations. Either case enhances frequency selectivity by reducing cross sensitivity.

Abstract: The cross sensitivity of a two-beam infrared gas analyzer is eliminated by using two differently long cells for the measuring gas in the two beam paths and by using an interference filter at least in the beam path containing the longer cell; the filter, however, does not filter the entire beam in that path.

Abstract: The cross-sensitivity of a two-beam infrared gas analyzer is reduced by using two differently long cells for the sample gas in the two beam paths. The path with the short sample gas cell is intercepted by a detector cell having highly absorbing wall while the detector cell in the other path is highly reflective, e.g., made of gold. The two detector cells are interconnected by a differential pressure chamber with capacitive pickup.

Abstract: The sensitivity and selectivity of a two beam analyzer operating with negative filtering and differential absorption-pressure detection is improved by employing differently long cells for the sample gas in the two beam paths, which reduces the effect resulting from overlapping absorption bands of the wanted and of unwanted components in the sample gas.

Abstract: Apparatus for determining the nitrogen oxide concentration in a gaseous mixture while minimizing measuring errors. The radiation from a hollow cathode lamp emitting the nitrogen oxide resonance radiation is modulated by a device for generating alternatively an unfiltered or test beam and a reference beam. The reference beam is filtered by a nitrogen oxide filled filter. An absorption cell is disposed in the path of the reference beam. Further, a monochromator or filter is provided and a detector for receiving the radiation from the monochromator filter. A signal processing unit is coupled to the detector for forming electric signals corresponding to the signal from the unfiltered and the reference beam and for forming the quotient thereof. A ray splitter is disposed in the path of the two beams to provide a different beam path and an additional radiation detector is disposed in the additional path.

Abstract: The two beam analyzer has chambers traversed by infrared beams and passed through by test gas; the intensity of each beam is detected by a detector having chambers which are filled with gas of the same type as the gas to be detected (as a trace) in the test gas. Additionally, one beam path includes a selectivity cuvette or cell, filled exclusively with that type of gas, but at a rather low pressure.