Recommendations for the calibration and evaluation of pH on site measuring instruments

Project Description

For several years, on site measuring instruments have been largely developed in various fields such as environment, process control.
They present two main advantages compared to classical laboratory instruments :

• no modification of the sample during transport and storage,
• instantaneous information facilitating the intervention of decision makers
   

Currently, very few standards are available for the evaluation and/or certification of these instruments in the environmental field. Some exist for ambient air, but almost none for water.
The implementation of the Water framework Directive and of the Measurement Instrumentation Directive will increase the need for standards in that field.

The purpose of this project is to produce new recommendations for the calibration and evaluation of pH on site measuring instruments in the field of water analysis. This project aims to be a pilot study focusing on pH but could be the basis for a set of new standards dealing with water quality monitoring in relation with the ISO standard 15839:2003 “Water quality - On-line sensors/analysing equipment for water - Specifications and performance tests”.

The project is divided into 3 parts :

study of the current ways of evaluating pH measuring instruments in the different field of water analysis : surface water, ground water, rain water and sea water. The first action will be to create a questionnaire to be sent to producers of equipment and to end users to know how they evaluate and calibrate their instruments. The purpose is to give an overview of the situation at a European level, each NMI being responsible of this study in its country,
redaction of protocols to be used for the evaluation of pH on site measuring instruments.
This will have to be done with the participation of producers and end users, validation of the protocols on typical equipment evaluated by NMIs and tested in the field.

This project intends to be considered as a study-case for the identification of processes and outcomes required for participation in trans-national research program based on Article 169

Final Report 2008-12-11

For several years, on site measuring instruments have been largely developed in various fields such as environment, process control...
They present two main advantages compared to classical laboratory instruments:

• no modification of the sample during transport and storage,
• instantaneous information facilitating the intervention of decision makers
   

Currently, very few standards are available for the evaluation and/or certification of these instruments in the environmental field. Some exist for ambient air, but almost none for water.
The implementation of the Water framework Directive and of the Measurement Instrumentation Directive will increase the need for standards in that field.
The purpose of this project was to produce new recommendations for the calibration and evaluation of pH on site measuring instruments in the field of water analysis. This project aimed to be a pilot study focusing on pH but could be the basis for a set of new standards dealing with water quality monitoring in relation with the ISO standard 15839:2003 “Water quality - On-line sensors/analysing equipment for water - Specifications and performance tests”.

• The first step of the project was to collect points of view and needs of users and producers. The reality in laboratories was evaluated through a questionnaire prepared by the LNE
• The second step was to write a protocol, according to the needs of users
• The third step was to circulate the document among users, along with a second questionnaire, in order to validate the protocol and verify whether users expectations were met
   

The final draft of the protocol, which takes into account the most relevant commentaries of users, is now completed.
The complete report can be received from the coordinator.