A FIRST REVIEW OF CALIBRATION DEVICES ACCEPTABLE FOR METROLOGY LABORATORY Mr Drago GROSELJ Dr Jérôme DUVERNOY Dr John GORMAN

2 Specialization  PRESSURE  TEMPERATURE  HUMIDITY ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

3 PRESSURE  Primary Pressure Standard M = Mass P = Piston C = Cylindre Weight = Pressure ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

4 PRESSURE  Primary Pressure Standards Dead weight gauge ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

5 PRESSURE  Advantages: –Traceability to mass and length –Long term stability –Accuracy, reproducibility, reliability and stability ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

6 PRESSURE  Disadvantages: –Time consuming –Measurements corrections (T, g, U…) ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

7 PRESSURE  Secondary Pressure Standard Quartz Barometer ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

8 PRESSURE  Advantages: –Faster and easier to use –Easy to adapt to automatic operation –Generally less expensive ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

9 PRESSURE  Disadvantages: –Not a basic measurement –Higher measurement uncertainty ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

10 PRESSURE  Travelling pressure standard An example of electronic barometer ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

11 PRESSURE  Calibration systems example of a barometric chamber ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

12 PRESSURE  Calibration systems example of a pressure generator ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

13 TEMPERATURE  EIT 90 ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA METEOROLOGY

14 TEMPERATURE  EIT 90 ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA Gallium Mercury Water

15 TEMPERATURE  Standard Platinum Resistance Thermometer (SPRT) Example of an SPRT ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

16 TEMPERATURE  Means of calibration Stirring bath ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

17 TEMPERATURE  Means of calibration Climatic chamber ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

18 HUMIDITY  Humidity Generators Two Pressure Humidity Generator ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

19 HUMIDITY  Humidity Generators Split stream system ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

20 HUMIDITY ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA  Climatic Chambers Environmental Chamber

21 HUMIDITY ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA  Climatic Chambers Split stream chamber

22 HUMIDITY  Salt Solutions Generator ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA Salt/Temperature o C Lithium chloride11.3 Magnesium chloride Potassium carbonate Sodium bromide Sodium chloride Potassium chloride Potassium sulphate

23 HUMIDITY  Salt Solutions Generator ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA The salt solution system at Meteo France

24 HUMIDITY  Approximate Uncertainties ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

25 HUMIDITY  Recommendations –The target uncertainty within a calibration laboratory = 2 % RH (0.3 o C dew point) –Labs should have a humidity generator or chamber: within the range 5 % RH at 15 o C to 90 % at 40 o C. –The streams or parcels should be stable to within ± 0.2% RH per minute –If the source of humidity is not a first principles device, then measurement of the humidity should be with a dew point hygrometer with an 95 % uncertainty of 0.2 o C or better –Calibration of field humidity probes should be done with a view to maintaining a low overall uncertainty. The whole of measurement cycle, including inspection frequency, must be considered and appropriate levels of calibration uncertainty applied ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

26 CONCLUSION  Some possibilities in terms of calibration.  This first review is not exhaustive  Every other remaining devices, standard, generator not presented here are still acceptable  Metrology is the science of measurement  Expression of the uncertainty ENVIRONMENTAL AGENCY OF THE REPUBLIC OF SLOVENIA

27 THE END THANKS FOR YOUR PATIENCE