NATIONAL OBSERVATORY OF ATHENS 
The LMDC also provides technical support for the use of meteorological sensors and instrumentation, as well as advisory services in the process of both selecting and installing meteorological equipment in other entities. Moreover, with its own calibrated sensors, the LMDC has the capability to perform specialized measurements for account of companies, institutions and entities from both public and private sector.
The laboratory is organized according to the Quality Assurance standards. LMDC’s Manual of Operations has been approved by the EAA Administration Council and calibrations are carried out according to International Standards. For all calibration procedures, the LMDC staff has drafted Technical Guidelines based on ISO standards, the current scientific best practice, ISO Guide on the expression of uncertainty in measurements, and the World Meteorological Organization (WMO)-No 8: “Guide to meteorological instruments and methods of observations”
Indicative Customers List
- Institute for Environmental Research and Sustainable Development (NOA).
- Public Power Corporation (PPC).
- Center of Renewable Energy Sources (CRES).
- AKTOR technical & construction company.
- SYNERGIA technical & consulting S.A.
- ENERDIA technical & construction company.
- SKY Development R.E.S. S.A.
- University of Ioannina.
- University of Aegean.
- University of Cyprus, PV Technology Laboratory.
- Cyprus Meteorological Dept., Ministry of Agriculture, Rural Development & Environment
Calibration Process
Calibration of Actinometers
In LMDC calibration of pyranometers is carried out according to ISO 9847:1992. According to this process, the istruments under calibration are placed in outdoor conditions, on a horizontal surface, close to the standard Kipp & Zonen CM21 pyranometer (Secondary Standard according to ISO 9060:1990 and High Quality according to WMO).Under constantly clear sky conditions, momentary measurements of electrical voltage are taken at the instruments output during whole daylight period and for solar altitude greater than 20 degrees.
Calibrations are carried out comparatively, using calibrated working standards, with readings traceable to the Global Radiometric Scale. This method is simple and provides sufficient accuracy because errors related to the dependence on solar incidence angle and the instrument's spectral response are avoided.
Traceability is ensured as the 'secondary standard' used in LMDC, is calibrated regularly at the World Radiation Center (WRC), in Davos, Switzerland.
Calibration of photometers is carried out in a manner analoqous to ISO 9847:1992, using a digital reference photometer LMT B510A, with an LMT P30SCT sensor, operational range 0.001-600000 Lux, accuracy of sensitivity better than +/ - 0.5%.
The cost of calibration is 180 euros per actinometer (plus VAT when applicable).
Calibration of Thermometers
According to the respective Technical Guidline followed in LMDC, instruments under calibration are placed together with the Pt-100 calibrated standard thermometer (ERTCO-Hart 850 High Precision RTD Thermometer and Isotech 100 Ohm PRT probe, type: 935-14-85) either in a thermostatic bath Isotech Oceanus model 809 (typical range -10°C ... +50° C), or in a controlled temperature chamber WTB Binder KB-53 (typical range 0°C ... +50° C).
LMIC's thermometer calibration process of is traceable to the International Temperature Scale 90 as the standard used is being calibrated regularly at the Hellenic Institute of Metrology (HIM), Thessaloniki, Greece.
The cost of calibration is 80 euros per thermometer (plus VAT when applicable).
Calibration of Hygrometers
According to the LMDC technical Guidline for hygrometer calibration, the instruments under calibration are either placed in a controlled relative humidity chamber (Theodor Friedrichs, type 8222) using as reference an Assmann pcychrometer (typical range 20%...100%) or exposed to the vapours of saturated solutions of lithium cloride (LiCl - 11.3%, 20°C), sodium cloride (NaCl - 75.5%, 20°C) and potassium sulfate (K2SO4 - 97.6%, 20°C).
The cost of calibration is 80 euros per hygrometer (plus VAT when applicable).In case of a combined digital thermo-hygrometer sensor, the cost of calibration is 100 euros per sensor (plus VAT when applicable).
Calibration of Precipitation Gauges
According to the LMDC Technical Guidline for rain gauges calibration, the instruments under calibration are supplied with a certain quantity of water in order to record the number of pulses or other output produced.
The cost of calibration is 70 euros per instrument (plus VAT when applicable).
Calibration of Barometers
According to the LMDC technical guideline for barometer calibration, the instruments under calibration are exposed to the prevailing ambient atmospheric pressure in parallel with the calibrated VAISALA PTB201A barometer.
Calibrations are carried out comparatively, using calibrated working standards, taking momentary measurements of electrical voltage over a period of several days. This method is simple and provides sufficient accuracy.
The cost of calibration is 120 euros per barometer (plus VAT when applicable).
Calibration Certificates
When a calibration process is completed, LMDC issues a ‘Certificate of Calibration’ for each calibrated sensor with the exception of liquid-in-glass thermometers where a certificate of good operation is provided.
NOTE: In case of calibration of 5 or more sensors of the same type, there is a 10% discount.
Calibration of Actinometers
In LMDC calibration of pyranometers is carried out according to ISO 9847:1992. According to this process, the istruments under calibration are placed in outdoor conditions, on a horizontal surface, close to the standard Kipp & Zonen CM21 pyranometer (Secondary Standard according to ISO 9060:1990 and High Quality according to WMO).Under constantly clear sky conditions, momentary measurements of electrical voltage are taken at the instruments output during whole daylight period and for solar altitude greater than 20 degrees.
Calibrations are carried out comparatively, using calibrated working standards, with readings traceable to the Global Radiometric Scale. This method is simple and provides sufficient accuracy because errors related to the dependence on solar incidence angle and the instrument's spectral response are avoided.
Traceability is ensured as the 'secondary standard' used in LMDC, is calibrated regularly at the World Radiation Center (WRC), in Davos, Switzerland.
Calibration of photometers is carried out in a manner analoqous to ISO 9847:1992, using a digital reference photometer LMT B510A, with an LMT P30SCT sensor, operational range 0.001-600000 Lux, accuracy of sensitivity better than +/ - 0.5%.
The cost of calibration is 180 euros per actinometer (plus VAT when applicable).
Calibration of Thermometers
According to the respective Technical Guidline followed in LMDC, instruments under calibration are placed together with the Pt-100 calibrated standard thermometer (ERTCO-Hart 850 High Precision RTD Thermometer and Isotech 100 Ohm PRT probe, type: 935-14-85) either in a thermostatic bath Isotech Oceanus model 809 (typical range -10°C ... +50° C), or in a controlled temperature chamber WTB Binder KB-53 (typical range 0°C ... +50° C).
LMIC's thermometer calibration process of is traceable to the International Temperature Scale 90 as the standard used is being calibrated regularly at the Hellenic Institute of Metrology (HIM), Thessaloniki, Greece.
The cost of calibration is 80 euros per thermometer (plus VAT when applicable).
Calibration of Hygrometers
According to the LMDC technical Guidline for hygrometer calibration, the instruments under calibration are either placed in a controlled relative humidity chamber (Theodor Friedrichs, type 8222) using as reference an Assmann pcychrometer (typical range 20%...100%) or exposed to the vapours of saturated solutions of lithium cloride (LiCl - 11.3%, 20°C), sodium cloride (NaCl - 75.5%, 20°C) and potassium sulfate (K2SO4 - 97.6%, 20°C).
The cost of calibration is 80 euros per hygrometer (plus VAT when applicable).In case of a combined digital thermo-hygrometer sensor, the cost of calibration is 100 euros per sensor (plus VAT when applicable).
Calibration of Precipitation Gauges
According to the LMDC Technical Guidline for rain gauges calibration, the instruments under calibration are supplied with a certain quantity of water in order to record the number of pulses or other output produced.
The cost of calibration is 70 euros per instrument (plus VAT when applicable).
Calibration of Barometers
According to the LMDC technical guideline for barometer calibration, the instruments under calibration are exposed to the prevailing ambient atmospheric pressure in parallel with the calibrated VAISALA PTB201A barometer.
Calibrations are carried out comparatively, using calibrated working standards, taking momentary measurements of electrical voltage over a period of several days. This method is simple and provides sufficient accuracy.
The cost of calibration is 120 euros per barometer (plus VAT when applicable).
Calibration Certificates
When a calibration process is completed, LMDC issues a ‘Certificate of Calibration’ for each calibrated sensor with the exception of liquid-in-glass thermometers where a certificate of good operation is provided.
NOTE: In case of calibration of 5 or more sensors of the same type, there is a 10% discount.