1,720,995 research outputs found
Temperature metrology needs for climate studies - CCT Recommendation to CIPM T3 (2010). Doc. CCT/10-09
No full text“Temperature metrology needs for climate studies” Report on the 25th Meeting of the Consultative Committee for Thermometry Maggio 2010. Doc. CCT/10-09
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Rapporto tecnico INRiM 20/2015 “Towards the definition of a ground based reference station for the generation of reference grade climate data”
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Influence of nonwoven fabrics physical parameters on the thermal and water vapour resistance
No full textRapporto tecnico INRiM 19/2015 “Measurement protocol for evaluation of siting uncertainty for air temperature measurements in three selected test sites”.
No full textRapporto tecnico INRiM 28/2012 “Taratura degli strumenti meteorologici in servizio presso l’osservatorio storico di Moncalieri”.
No full textComparative analysis of the influence of solar radiation screen ageing on temperature measurements by means of weather stations
No full textSolar radiation screens play a key role in automatic weather stations (AWS) performances. In this work, screen ageing effects on temperature measurements are examined. Paired temperature observations, traceable to national standards and with a well-defined uncertainty budget, were performed employing two naturally ventilated weather stations equipped with identical sensors and different only for their working time. Three different tests were carried out employing different aged AWSs: a 5-year-old AWS (AWS5) was compared with a new device (AWS0), a 1year old (AWS1) was compared with both a 3years old (AWS3) and a new one devices (AWS00). Due to solar and weather conditions exposure a degradation of the screen reflective coating is evident for the older AWSs (5 and 3years old) and so a qualitative estimation of how different conditions of ageing affect the temperature drift was done. During the comparison 0 to 5 and 1 to 3-year-old screens, significant temperature differences were recorded at different times of the day. The differences, wider than the uncertainty amplitude, demonstrate a systematic effect. The temperature measured with the older screen is larger, and the maximum instantaneous difference was 1.63 degrees C (for 0-5years comparison) in daytime hours. During night-time the two AWS's measure the same temperature (within the uncertainty amplitude). This behaviour, increasing with increasing solar radiation intensity and decreasing with increasing wind speed, is attributed to a radiative heating effect. The screen ageing has compromised the shield effectiveness introducing a significant change in the temperature evaluation. The experimental results of a further comparison, between 0- and 1-year-old screens, confirm the same conclusion showing a negligible ageing effect, within the uncertainty amplitude
Traceability and Online Publication of Weather Station Measurements of Temperature, Pressure, and Humidity
No full textA project to enhance the quality of climate data has been running at the Italian Institute of Metrology (INRiM) since 2007. The focus of the project has been the installation and development of a weather station to monitor temperature, air humidity, and pressure; the collection and storage of the measurements; and the provision online to allow open-access. The project aims to improve the traceability of measurement through development of calibration and measurement protocols able to be applied to the wide variety and geographical spread of weather stations. The data collected have a short traceability to the national standards and a well-known uncertainty budget. In this work the project progress in terms of data collection and calibration of the weather station is reported. The instant measured values of the weather parameters have been published online, as is a complete database of the recordings, stored in daily, monthly, and annually collected data archives. This is the first example at the Italian national level of an archive of reliable climate data open to public access. A traceability study was carried out through calibration of the weather station instruments both in situ (over the course of one seven-hour period) and in the laboratory (under the full range of expected temperature, humidity, and pressure conditions). Significant differences in the results of the two calibrations are noted and implications for the provision of traceability discussed
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