JERICO. ILC Evaluation report Conductivity/Salinity Temperature/Dissolved Oxygen. Annex to Deliverable D #1.6

Complemental to the first FCT workshop, the metrology laboratory of Ifremer Centre de Bretagne carried out a calibration experiment from the 8th to the 12th of October 2012. This experiment was promoted by the Jerico European project (JOINT EUROPEAN RESEARCH INFRASTRUCTURE NETWORK FOR COASTAL OBSERVATORIES), in the framework of a collaborative work proposed by the workpackage 4, “Maintenance and Calibration”, and the “Forum for Coastal Technologies”. The purpose of this experiment was to compare the calibration methods used by different institutes or firms within an inter-laboratory comparison (ILC). In terms of metrology, this comparison will allow the laboratories to assess their performance with respect to the calibration of their sensors. The parameters under investigation were temperature, salinity (conductivity) and dissolved oxygen. To simplify the process and to shorten the time devoted to the comparison, Ifremer proposed to carry out for each participant, a bilateral comparison (Ifremer vs participant) on one or several sensors owned by the participant. All comparisons were simultaneous. The objective (institutes performance) was achieved by comparing the calibration results of the regular calibration of the sensors of the participants with the reference calibrations performed by the coordinating laboratory, the metrology laboratory of Ifremer. The evaluation of the performance was carried out using the reported deviations and/or corrections and corresponding uncertainties of the participants with respect to the measured deviations/corrections and corresponding uncertainties by the reference laborator

Méthode pour la mesure de pH des eaux marines. Note de positionnement

Cette note a été préparée dans le cadre du programme scientifique et technique AQUAREF pour l'année 2019, dans le cadre du thème « A » « Eléments d'aide à la décision pour l'élaboration et la mise en oeuvre de la politique de surveillance »

A dissolved oxygen calibration bench

This paper presents a metrology bench dedicated to the calibration of optical dissolved oxygen sensors. This set up is used at Ifremer metrology laboratory to calibrate dissolved oxygen sensors integrated on oceanographic probes. The characterization of the bench is seen through the analysis of its stability and its homogeneity. An application is proposed on the calibration of Aanderaa 3835 and 4330 optodes

The effect of the salinity level on conductivity sensor calibration

This paper presents a study on the calibration of conductivity sensors. The puropse is to demonstrate the effect of the salinity concentration on the response of conductivity sensor. Several experiments are performed on three sensors of different technologies: a Seabird Sbe37-SIP MicroCAT, a Falmouth Scientific Inc. IMCTD-MBP-D and a NKE Instrumentation Smatch. The analysis of the results shows an overall impact of the salinity level on the sensor response. This effect is discussed regarding the oceanographic requirements

Spectrophotometric method for the determination of the pHT of sea water

Cet article présente la méthode spectrophotométrique mise en place au laboratoire de métrologie de l’fremer, afin de déterminer le pHT de l’eau de mer grâce à l’indicateur coloré pourpre de m-cresol. Le but est de décrire précisément cette méthode (matériel et mode-opératoire), ses difficultés, ainsi que les paramètres ayant un impact sur le pHT. Les résultats d’une comparaison inter-laboratoires menée par le JAMSTEC (Japan Agency for Marine-Earth Science and Technology) seront présentés, suivis d’une réflexion portant sur cette méthode ainsi que les exigences océanographiques mises en jeu

JERICO. Report on Calibration Best Practices

The main goal of work package 4 is to increase the performance of oceanographic observatories in Europe. One major point is the formulation and the evaluation of best practises of sensor calibration. This is an issue of great interest for institutions dealing with different (automated) observation systems. So, this report is providing information about the best practises for sensor calibration of different types of sensors. Each sensor type has typical characteristics, which have to be addressed when calibration routine has to be applied to the sensor. This is outlined in the next sections for the different sensor types. However, there are also several general advices for sensor calibration which are valid for any sensor when reliable sensor data are needed. Temperature and conductivity sensors cannot be calibrated in the field, so thoroughly lab calibration is necessary, i.e. the preparing and maintaining of temperature baths. For Chlorophyll sensors it is generally agreed that FChla measurements do not necessarily reflect true analytically measured [Chla], so this has to be taken into account when calibrating chlorophyll fluorescence sensors. No generally accepted method for fluorometer calibration exists, so also manufacturers have different conventions. Various solutions for primary fluorometer calibration include factory calibration, use of algae cultures, chemical standards dissolved in water or in various solvents, or solid standards. Calibration of chemical sensors relies strongly on proper handling of water samples and reagents and the preparing of standard solutions. Monitoring of more than one nutrient parameter with one device has to be carried out carefully. For oxygen sensors the according calibration routine relies on comparing lab analyses via Winkler titration which needs some experience to carry out including proper sampling. A wide range of different concentration levels and different temperature levels must be used for calibration of optical oxygen sensors

Essais d’aptitude par comparaison inter-analystes pour l’évaluation des performances de l’indicateur Macrophytes en milieu lagunaire poly-euhalin

The spatial and temporal variability of macrophyte sampling in polyhaline lagoons (with an annual average salinity of >18 PSU) in the context of the EU's Water Framework Directive is well estimated. However, there is a need to better define the variability of in-situ observations (evaluating coverage) between and among team members. This Inter-Laboratory Comparison (ILC) is based on in situ observations and was conducted with service providers with whom we usually perform our diagnostics, while implementing the specific DCE macrophyte protocol for poly-euhaline lagoons.La variabilité spatiale et temporelle des prélèvements de macrophytes réalisés sur les lagunes poly-euhalines (salinité moyenne annuelle >18 PSU) dans le cadre de la DCE est bien estimée. En revanche, la variabilité, entre agent d'une même équipe et inter-équipe, liée aux observations réalisées in situ (évaluation du recouvrement) reste à préciser. Cette Comparaison Inter Laboratoire (CIL) s’appuie sur des observations in situ et a été réalisée avec les prestataires avec qui nous réalisons habituellement nos diagnostics en mettant en oeuvre le protocole DCE macrophyte spécifique aux lagunes poly-euhaline

Fixed Observatories and LongTime-series of Dissolved Oxygen Measurements: Good Quality Data is a Challenge

International audienc