Back

Evaluation of measurement instrument performance for environmental monitoring

European directives have established quality objectives for purposes of monitoring the environment, air and water. In response to these directives, more extensive use is being made of online instruments, whose performance still needs to be evaluated prior to deployment. In this context, LNE is on hand to guide these kinds of performance evaluations.

Proposed services

Provision of the following services within the scope of measuring campaigns dedicated to chemical and physicochemical pollutants.

- Determining instrument performance in accordance with the currently accepted benchmark, in the aim of validating the measurement method:

Reliability (accuracy, detection and quantification limits, linearity, etc.),
Use conditions and protocol,
Instrument malfunctions under actual operating conditions,
Influence of interfering agents (chemical, biological, environmental, etc.) on the measurement result,
Calibration (frequency, type, etc.),
Interpretation of results.

- Expertise acquired in the development of new devices with respect to existing benchmarks.

Resources

To proceed with the provision of these services, LNE has at its disposal a set of tools that evaluate the performance of measurement instruments and methods first in the laboratory and then in the field, covering a wide range of environmental contexts and following specific protocols.

The methodologies employed rely on protocols for evaluating measurement device performance, as developed within the scope of either the ETV program launched by the American Environmental Protection Agency (EPA), standardization campaigns (e.g. NF EN ISO 15839 (2006), NF EN 16479, prEN 17075, TC 264 WI 00264179, OIML recommendations) or European metrology projects (JRP MacPoll, JRP Key-VOCs),

These methodologies make use of accredited reference approaches, as well as reference indicators, calibration benches built to the highest level of metrological precision and statistical tools applied to both validating methods and evaluating measurement uncertainty;
Performance under controlled conditions (i.e. in the laboratory) can then be compared to what has been obtained under actual operating conditions (i.e. in the field).

Gas analysis:

Technique	Specifications	Instrumentation use
Gas-phase chromatography	Various detectors: FID, TCD, HID, MS	Identification and quantification of gaseous pollutants
Fourier-transform infrared spectrometry	Long optical path cell Low concentrations (nmol/mol)	Identification and quantification of gaseous pollutants
Laser spectrometry (QC- Laser)	Low concentrations (nmol/mol)	Quantification of gaseous pollutants
CRDS spectroscopy (Cavity Ring-Down Spectroscopy)	Low concentrations (nmol/mol)	Quantification of gaseous pollutants

A4F-UV-DRI-MALS-ICPMS, Pastel UV analyzer (NO3, TOC, SS, etc.), Multi-parameter probe YSI EXO 2 (pH, conductivity, dissolved oxygen, turbidity, NO3, CDOM), Portable spectrophotometer NOVA60, etc.

Aerosol geneation:

Technique	Specifications	Instrumentation use
Nebulizer	Generation range: 100 nm - 1 µm	Adapted to the generation of aerosols via a wet process (e.g. colloidal suspensions)
Electrospray	Generation range: 5 nm - 150 nm	Adapted to the generation of aerosols via a wet process (e.g. colloidal suspensions)
Vortex Shaker	Generation range: PM10, PM2.5, submicron and supermicron aerosols	Adapted to the generation of aerosols via a dry process (e.g. powders, aggregates). Generator adapted to measuring the pulverulence (dustiness) of nano-structured powders
Generator, by electrical discharge	Generation range: a few nm - 200 nm	Adapted to the generation of carbon, copper, silver, aluminum aerosols, etc.

A4F-UV-DRI-MALS-ICPMS, Pastel UV analyzer (NO3, TOC, SS, etc.), Multi-parameter probe YSI EXO 2 (pH, conductivity, dissolved oxygen, turbidity, NO3, CDOM), Portable spectrophotometer NOVA60, etc.

Characterization of particle monitoring instruments:

Technique	Specifications	Instrumentation use
SMPS (Scanning Mobility Particle Sizer)	Measurement range: 5 – 1,000 nm Minimum temporal resolution on the order of one minute	Size distribution measurement of suspended particles (both diameter and concentration)
DMS (Dynamic Mobility spectrometer)	Measurement range: 5 – 1,000 nm Minimum temporal resolution on the order of one minute	Size distribution measurement of suspended particles (both diameter and concentration)
APS (Aerodynamic Particle Sizer)	Measurement range: 0.5 – 20 µm Minimum temporal resolution of one second	Size distribution measurement of suspended particles (both diameter and concentration)
CPC (Condensation Particle Counter)	Measurement range: 5 – 2,000 nm In real time	Concentration measurement, in terms of number of particles
TEOM (Tapered Element Oscillating Microbalance)	Resolution in mass concentration, µg/m3 Temporal resolution of 2 seconds	Concentration measurement, in terms of particle mass
Liquid phase chromatography	LC-HRMS LC-MS/MS
Ion plasma chromatography	HR-ICP-MS

A4F-UV-DRI-MALS-ICPMS, Pastel UV analyzer (NO3, TOC, SS, etc.), Multi-parameter probe YSI EXO 2 (pH, conductivity, dissolved oxygen, turbidity, NO3, CDOM)

Portable spectrophotometer NOVA60, etc.

Regulations

Directive 2008/50/EC, with threshold exposure values (ANSES, INRS).

Products involved

All measurement instruments used to monitor the environment, water and air.