Assessing Setups of a Multigas Analyser for Noxious Gas Monitoring in an Open Dairy Barn

The measurements of gas concentrations represent a relevant step for the es-timation of emission rate of ammonia and greenhouse gases from livestock buildings. Based on the research studies, the strategy applied for gas monitor-ing in open and semi-open dairy houses can optimise data collection and the reliability of the measurements. Since the photo-acoustic spectroscopy system (INNOVA by LumaSense Technologies A/S, Denmark) is commonly used for scientific purposes in the context of livestock building, this research study aims at refining knowledge on the measurement set-up of the instrument with in-field experiment. Data of gas concentrations (NH3, CH4, and CO2) at different sampling locations (SLs) and set-up were continuously recorded in a semi-open dairy barn. Two differentdatasets were selected to compute the variability associated to dif-ferent set-up of the instrument related to the Sample Integration Time (SIT) and the number of repetitions for each SLS. Then, the one-way analyses of variance were applied to evaluate significant differences for groups of data. Based on the results, the INNOVA set-up influenced the measurement strate-gy as well as the localisation of sampling locations (SLs). In detail, the SIT set-up of INNOVA influences the duration of a measurement cycle by the device. Moreover, there was not a significant difference between the varia-bility on concentrations with SIT5 and SIT20 (P>0.05). Therefore, the set-up with SIT5 is more suitable than SIT20 since it allowed to complete a meas-urement cycle in less than one hour with 12 SLs and 3 repetitions. Conse-quently, the number of repetitions executed for each measurement had a significant influence on the design of the sampling strategy.