Tm. Brownbrandl et al., MODIFICATION, OPERATION, AND ERROR ANALYSIS OF AN INDIRECT CALORIMETER FOR WITHIN-CHAMBER CONTROL AND DATA-ACQUISITION, Transactions of the ASAE, 41(4), 1998, pp. 1115-1118
An existing environmental chamber for short-term indirect calorimetric
studies was re-configured far use as a within-chamber recirculation u
nit with a computerized control and data acquisition system, and modif
ied with an in-chamber humidity control unit to provide 30 to 80% RH.
Intake air was pre-conditioned to a specific temperature-humidity stat
e point and delivered at 20 to 50 standard L/min. Data can be collecte
d from the chamber to a computer via an 8 channel amplifying/filtering
unit and an analog-digital converter. The computer also controlled th
e environmental conditions in chamber. Over a series of ''dry'' runs (
without animals), system error for dry bulb temperature varied from +/
-0.2 degrees C to +/-1.1 degrees C with an average error of 0.4 degree
s C. Average moisture production and CO2 errors were 6.5% and 1.4%, re
spectively, from a of animal tests. All were within acceptable limits
for reliable data generation.