A dual-respiration chamber system with automated calibration

Abstract

Schoffelen, Paul F. M., Klaas R. Westerterp, Wim H. M. Saris, and Foppe Ten Hoor. A dual-respiration chamber system with automated calibration. J. Appl. Physiol. 83(6): 2064–2072, 1997.—This study characterizes respiration chambers with fully automated calibration. The system consists of two 14-m³pull-type chambers. Care was taken to provide a friendly environment for the subjects, with the possibility of social contact during the experiment. Gas analysis was automated to correct for analyzer drift and barometric pressure variations and to provide ease of use. Methods used for checking the system’s performance are described. The gas-analysis repeatability was within 0.002%. Results of alcohol combustion (50–350 ml/min CO₂) show an accuracy of 0.5 ± 2.0 (SD) % for O₂consumption and −0.3 ± 1.6% for CO₂ production for 2- to 24-h experiments. It is concluded that response time is not the main factor with respect to the smallest practical measurement interval (duration); volume, mixing, gas-analysis accuracy, and levels of O₂ consumption and CO₂ production are at least equally important. The smallest practical interval was 15–25 min, as also found with most chamber systems described in the literature. We chose to standardize 0.5 h as the minimum measurement interval.