Carmen Garca Izquierdo Centro Espaol de Metrologa Proposal of traceable measurements of permafrost temperature by optical fiber Carmen Garca Izquierdo, CEM, Spain Head of Contact Thermometry Carmen Garca Izquierdo, CEM, Spain Head of Contact Thermometry Carmen Garca Izquierdo Head of Contact Thermometry of CEM, 2001 Member: Euramet ENV TG BIPM-CCT ENV TG WMO-CIMO Expert team on instrument intercomparison The CENTRO ESPAOL DE METROLOGA is the Spanish National Metrology Institute responsible for the maintenance and dissemination of the national standards of the IS Units. The TEMPERATURE Division is responsible for the development, maintenance and dissemination of the unit of thermodynamic temperature: the kelvin, by means of the International Temperature Scale of 1990 (ITS-90). Nowadays, The Centro Espaol de Metrologa realizes the ITS-90 from -189,3442 C (triple point of argon) up to 2200 C. Contact Thermometry/primary laboratory: -Calibration of SPRT in fixed points: (T.P. Ar:-189 C, F.P. Ag: 961,78 C) -Calibration and study of CSPRT in fixed points -Calibration of water triple point cells -Assembly of mercury triple points cells (~ -39 C) Contact Thermometry/secondary laboratory: -Calibration by comparison: IPRT (Pt-100), digital thermometers, liquid in glass thermometers, thermistors, thermocouples -Calibration in fixed points: Nobel metal thermocouples -Characterization of calibration baths, climate chambers, furnaces Carmen Garca Izquierdo, CEM, Spain Head of Contact Thermometry MeteoMet1. Air Temperature sensors: Study of the influence of the radiation shield in the calibration of thermometers Study of the drift of air temperature sensors under extreme salinity environments Carmen Garca Izquierdo, CEM, Spain Sensor failure MeteoMet2 Leader of WP on land : the coordination of :14 NMIs 151,8 men/month 43 deliverables Carmen Garca Izquierdo, CEM, Spain Technical activities: LAND -Study the behaviour of temperature sensors in extreme conditions of T and H.R. -Study the influence of the buildings in air temperature measurements -Calibration of Ultrasonic anemometer as a thermometer -Protocol for the instruments intercomparions. SEA, CSIC and UPC - Temperature Calibration of CTD seabirds -Design, built, calibration and use of fiber optics as thermometer: Determination of sea surface and sea profile temperature Study the drift of the CTD Measurement of permafrost profile temperature by optical fiber Proposals, Future activities Current Techniques : -Pt-100, Thermistors - Invasive -Conduction errors in the temperature of active layer? -Wide cables -Light Radiation errors? Critical in the Arctic since the sun light is different in each season -Selfheating? - Drift? Fiber Bragg grating : -Are not affected by electromagnetic radiation -No transmitters of electromagnetic radiation, no temperature change -Little size and light: Non invasive -Remote control -Easy multiplexing in one device -No drift in short term Carmen Garca Izquierdo, CEM, Spain Proposals, Future activities -Design a new optical sensor based in Fiber Bragg grating -Temperature measurement points in agreement with the experimental site -Traceable calibration of the designed device in wavelength and as thermometer -Experimental measurements -Evaluation of the sensor drift -Comparison of the current techniques with the optical fiber at INRiM device (Designed and characterized in MeteoMet2 project) - Establishment of model function and uncertainty evaluation Other proposals: Proposals, Future activities -Comparison of snow surface temperature measured by contact and non contact methods. Uncertainties? -Quantities of influence in air temperature measurements. Direct sun radiation influence? -Sea temperature measurements. Definitions of SST? Model functions ? Uncertainties? -More ideas? More problems? Carmen Garca Izquierdo, CEM, Spain Thank you Carmen Garca Izquierdo, CEM, Spain