Evaluation of a Miniature Carbon Dioxide Sensor to Control End- Expired Air Sampling in a Multi-breath Sampling Device.
NIOSH 1993 Nov:25 pages
In an effort to obtain end expired sampling of large volumes of exhaled air, a commercially available miniature carbon-dioxide (124389) sensor was interfaced to a multibreath sampling device. A description was provided of the needed modifications to the sensor regarding electronics and hardware configurations. Tests indicate that the sensor was able to accurately control a gate on the sampler to permit collection of end expired breath samples during normal continuous tidal breathing. While testing the device it was noted that sidestream sampling was imprecise and significantly biased relative to mainstream sampling. If the sidestream sampling gate were controlled to open at the end of each breath, end expired sampling of each breath should be feasible. In this manner it would be possible to trace blood concentrations of xenobiotics and make proper estimates based from sampling large volumes of expired air. The authors note that the proprietary solid state infrared carbon- dioxide sensor failed during these trials, and that no commercially available substitute was found.
NIOSH-Author; Sampling-equipment; Air-samplers; Biological-monitoring; Lung-function; Respiratory-gases; Air-sampling-techniques;
NTIS Accession No.
Division of Physical Sciences and Engineering, NIOSH, Cincinnati, Ohio, 25 pages, 7 references