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Updated: Jan 25, 2026

Safety Precautions and Operating Procedures in an ABSL-4 Laboratory: 1. Biosafety Level 4 Suit Laboratory Suite Entry and Exit Procedures
Published on: October 3, 2016
Water Activity Tester Suited to Compliance and High Aw Work
Anthony N Sharpe1, Marcel P Diotte1, Istvan Dudas1
1Bureau of Microbial Hazards, Food Directorate, Health Protection Branch, Health and Welfare Canada, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2.
Abstract:
A thermometric device unequivocably showed whether samples complied with a standard, to a resolution better than 0.002 aw units, without calibration, and with a throughput of one sample per 6 min. As a meter its response was linear from aw = 0.78 (the lowest value tested) to 1.00. It exhibited no hysteresis and was immune to drift resulting from high humidities or contamination by nonaqueous volatiles from foods.
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