Frost/Dew Point Temperature and Relative Humidity Measurements: Primary and Secondary Calibration Methods
Year: 2025
Type: conference-paper
Abstract: Humidity measurements are crucial across various industries to ensure product quality, safety, and process efficiency. These measurements can be expressed as absolute quantities, such as frost/dew point, temperatures point, tf/td, or as relative humidity, U, which relates to saturation at a given temperature. Chilled-mirror hygrometers are widely used in high-precision industrial and research applications due to their broad measurement range, stability, and accuracy. Ensuring metrological traceability requires rigorous calibration using traceable methods. The DAkkS-accredited Calibration Laboratory of Process Insights follows DKD-R 5-8 [1] guidelines and meets ISO 17025 [2] requirements, employing both primary and secondary calibration methods for tf/td over the range [-90, 95] °C, and U over the range [1, 98] %rh. Primary calibration achieves the lowest uncertainties using in-house 1-pressure and 2-pressure humidity (Utf/tf : 0.4 K - 45 mK and UU: 0.10 - 0.39 %rh), while secondary calibration relies on stable CM hygrometers and commercial humidity generators (Utf/tf : 0.54 K - 70 mK and UU: 0.10 - 0.49 %rh). For relative humidity calibration, both tf/td [1] and temperature [3] sensors require calibration. Humidity calculations follow established references, ensuring high accuracy [4, 7-8]. This work outlines the methodologies and challenges in maintaining traceability and accuracy in high accuracy humidity measurements at PI Cal.
Source: EPJ Web of Conferences
Authors: Andreia Furtado, Fitsum Zenebe, Özkan Subas, Michael Schwinghammer, Praveen Giri
Language: English
Subfield: Statistics, Probability and Uncertainty
Field: Decision Sciences
Domain: Social Sciences
Open Access status: diamond
OpenAlex ID: W4409208610