Work we can Perform
A distinction needs to be made between calibration (deviation points in the linearity test) from other tests which cannot be accredited as calibration (repeatability, limits, response time, response factor, conversion rate, sensitivity to an interfering factor, effect of power supply variations, flow rates, pressure, temperature, humidity, vibration and so on).
The laboratory performs the following activities:
Calibration with 1 to 7 points on the scale (test accredited on display and analogue output) ;
– Linearity at 7 to 12 points on the scale including zero (test accredited on the display and analogue output) ;
– Calibration curve and function (test accredited on the display and analogue output) ;
– Repeatability (zero and scale point) at 20 points (test not accredited on analogue or digital output) ;
– Limits detemined by graphical method (test not accredited on analogue or digital output) ;
– Response factor for FID analyzers (test not accredited on analogue or digital output) ;
– NO2 conversion rate for chemiluminescence (test not accredited on analogue or digital output) ;
– Ethane elimination rate for FIDs with oxidation oven (test not accredited on analogue or digital output) ;
– Response time (test not accredited on analogue or digital output) ;
– Interference (test not accredited on analogue or digital output).
The level of interfering factors can vary depending on the general standard or on specific standards (state which standard to follow in your request).
The certified reference materials have three consituents or less (air matrix).
Certified reference materials and pure gases are diluted in nitrogen or in air.
The calibration range is published on the website www.cofrac.fr (accreditation range or technical appendix).
Better uncertainty on reference concentrations obtained
The accreditation scope is used to estimate the best absolute uncertainty knowing the full scale of the instrument to be calibrated.
Other useful information regarding tests
Point of scale for repeatability (20 consecutive points): 80 % of full scale
Concentration of interfering gases following NF EN 15267-3 (other compliances can be used):
– O2: 3% vol. and 21% vol.
– CO: 300 mg/m3;
– CO2: 15% vol.;
– CH4: 50 mg/m3;
– N2O: 20 mg/m3 and 100 mg/m3 (fluidized bed combustion);
– NO: 300 mg/m3;
– NO2: 30 mg/m3;
– SO2: 200 mg/m3 and 1000 mg/m3 (coal fired thermal power plants without desulfurization).
Other gas levels are possible according different compliances. Please mention the specific compliance on your request.
Accreditation of the laboratory in accordance with ISO 17025 reference provides proof of the laboratory’s technical capability in the gas analyzers domain. The accreditation requires an effective quality management system. The laboratory also complies with the principles of ISO 9001:2000. Work carried out under accreditation is described in the scope of the accreditation of the laboratory.
The results of calibration under accreditation are recorded using the SI system of units.
Except there is a special client request, the specified requirements are the instrument manufacturer specifications (to be enclosed with your request for obsolete equipment).