Comparison between low-end discrete and high-end continuous measurements of air quality in swine buildings

Temperature and gas (ammonia, carbon dioxide, and hydrogen sulfide) concent rations were measured with portable instrumentation and compared with measu rements taken by a continuous system with automated benchtop gas analyzers in four tunnel-ventilated commercial swine finishing buildings. Measurement s of ammonia and hydrogen sulfide concentrations did not differ significant ly with respect to equipment used. However, carbon dioxide concentrations w ere different, and on average the portable instrument measurements were 40% lower during summer and 29% lower during winter. These discrepancies sugge st that carbon dioxide spatial variation may be significant. Conscientiousl y operated portable instrumentation can be used to effectively characterize air quality parameters within the animal environment.