Abstract: Quantitative colorimetric carbon dioxide measurement and measurement systems and methods are disclosed. The methods can include methods for calibrating a chemical colorimetric indicator used in the quantitative colorimetric carbon dioxide measurement system. Apparatuses are disclosed including a cartridge comprising a chemical colorimetric indicator that is configured to removably engage with a quantitative colorimetric measurement system. Cartridges containing a sealed container comprising a reference gas with a known concentration of carbon dioxide are also disclosed. Systems and methods for humidifying the chemical colorimetric indicator are also provided. Methods for using the systems are also disclosed including providing a breathing therapy to a patient or user.

Abstract: Infrared radiation emitter units for gas analyzers and other applications. The emitter has a substrate with a film of electrically resistive, emissive material on one of its surfaces. The emitter is so mounted on an emitter unit base that it can freely expand as the emitter heats up. A lead frame commutator, employed to electrically connect the emitter to an external power source, also facilitates the assembly of the unit. A component with a plated, parabolic surface collimates and focuses into an appropriate beam the energy generated by the emitter.

Abstract: Power supplies for generating a stream of electrical pulses in which successive pulses have opposite polarities. The pulses are formed and outputted from pulse generating circuitry which has two complementary pairs of MOSFETs arranged in an H-bridge configuration. Other major components of the power supply are voltage regulators for supplying positive and negative operating pulses with selected, precisely controlled voltages to the driver and watchdog circuits for disenabling the pulse outputting circuitry if: the frequency of the operating pulses deviate from a selected range, the widths of the operating pulses exceed a selected maximum, extraneous pulses are present, or the voltage of the operating pulses falls below or exceeds selected maximums. In one important application, the power supply is employed to drive the emitter of an infrared radiation source.

Abstract: A method of and device for calibrating infrared radiation transducers. A concentration factor representing the ratio of a data signal to a reference signal for a known concentration of a designated gas in a sample containing that gas is generated. The concentration factor is stored and used during subsequent calibration procedures. The calibration device has a zero cell and a span cell with windows for transmitting infrared radiation and radiation reflecting or absorbing material in the span cell. The span cell therefore provides a known and consistent level of radiation absorption.