Centre for Chemistry
Ing. Miroslava Vaľková
Director of the Centre
tel.: 02/60294 211
fax.: 02/60294 561
e-mail: valkova@smu.gov.sk
Eva Igazová
Secretariat
tel.: 02/60294518
fax.: 02/60294 561
e-mail: igazova@smu.gov.sk
ELECTROCHEMISTRY LABORATORY
1. AMOUNT OF SUBSTANCE (Inorganic analysis)
Quantity - Amount of substance
Unit - the mole is the amount of substance of a system which constains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12; its symbol is "mol". When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. The mole is a base unit of the Systeme International d'Unites.
Tasks
The main task is the realisation of base unit mole and its transfer into reference materials.
International comparisons
The accuracy of measurement is substantiated by comparisons organised by BIPM (CCQM-P7, CCQM-P19.1, CCQM-K8, CCQM-P36, CCQM-K42, CCQM-K29, CCQM-K59).
Available metrological services
Certified reference materials (CMRs) of chemical composition - pure substances with expanded uncertainty 0.004 % to 0.012 % and calibration solutions with expanded uncertainty 0.2 % to 0.3 %.
Methods of measurement:
- the amount content in primary CRMs is certified by high-accuracy coulometric titration.
- the mass concentration of monoelemental or anion calibration solutions is certified by refined methods of classical analysis traceable to primary CRMs or directly on the National Standard.
Instruments in use
High accuracy coulometric equipment, declared as National Standard for Amount of Substance. Measuring range is 0.0001 mol to 0.01 mol. The measurements are traceable to the value of the Faraday constant and Slovak standards of electric resistance, voltage, time and mass.
Contact
Dr. Michal Máriássy
phone: + 421 2 60294 522
e-mail: mariassy@smu.gov.sk
--------------------------------------------------------------------------------
2. pH
Quantity - pH.
Unit - dimensionless.
Tasks
The main task is the realisation of the unit of pH. The unit is further transfered by means of Certified Reference Materials.
International comparisons
The accuracy of measurement substiated organised by BIPM (CCQM-K9, CCQM-K17, CCQM-P37, CCQM-P52, CCQM-K18) and organised by COOMET 322/Ru/04.
Available metrological services
Establishing of traceability of pH by the means of CRMs. Production and distribution of primary cerified reference materials - buffers pH range from 1 to 10 with expanded uncertainty 0.005 - 0.02.
Methods of measurement:
- primary buffers are certified by definition method in Harned's cell,
- secondary CRMs of I. order are traceabled to primary CRMs by measurement in the definition cell with two hydrogen electrodes,
- secondary CRMs of II. order are traceabled to primary CRMs by measurement in the cell with transfer through a glass electrode.
Traceability is disseminated by means of primary CRMs in the following nominal values: 1.679; 4.000; 7.000; 9.180; 10.000.
Instruments in use
A National Standard equipment for a determination of defined pH values, consists of hydrogen electrodes, silver - silver chloride electrodes, cell without junction potencial, high purity conditioned hydrogen.
pH range of measurement within 1 to 10.
Expanded uncertainty (k=2) of pH measurement 0.002 to 0.005. Temperature range of measurement 10°C to 60°C.
Contact
Dr. Anna Mathiasová
phone: + 421 2 60294 226
mathiasova@smu.gov.sk
Mr. Leoš Vyskočil
phone: + 421 2 60294 225
vyskocil@smu.gov.sk
--------------------------------------------------------------------------------
3. ELECTROLYTIC CONDUCTIVITY
Quantity - electrolytic conductivity.
Unit - the unit of electrolytic conductivity is S/m (Siemens per meter). It is defined as the conductivity between two oposite faces of the cube with 1 m edge, filled with the measured solution.
Tasks
The main tasks are maintenance, improvement of the realisation and dissemination of the unit of electrolytic conductivity, realisation of the primary standard and certification of the primary Certifed Reference Materials (CRMs) as a means for certification of secondary CRMs. Traceability chain is realised by means of CRMs
International comparisons
2001 - Trilateral measurement comparison - PTB (DE), SMU (SK), UkrCSM (UA); pilot SMU.
2001 - CCQM-P22 (pilot DFM)
2003 - CCQM-P47 (pilot NMi)
2005 - CCQM-K36 (pilot DFM)
Available metrological services
Production of electrolytic conductivity CRMs with following nominal values: 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1 and 2 S/m. Calibration of conductivity cells. Calibration of solutions supplied by the customer
Methods of measurement:
The measurement system for conductivity is based on the comparison bridge method in a two-electrode Jones cell. The primary RMs (water solutions of KCI) are measured by means of primary standard od electrolytic conductivity in the measuring range of 0.01 - 2 S/m at the temperature of 25.00°C.
Instruments in use
Measurement of electrolytic conductivity is performed in a cell with exchangeable central tube whose length and cross-section are known. Conductivity is measured by means of an alternating current at a 1000 Hz frequency
Metrological parameters: conductivity range is 0.01 S/m - 2 S/m; relative standard uncertainty, type A is EA = 0.00006; relative standard uncertainty, type B is EB = 0.00023; relative combined standard uncertainty is EC = 0.00024.
Contact
Mr. Leoš Vyskočil
phone: + 421 2 60294 225
vyskocil@smu.gov.sk
GASES
1. MOLE FRACTION IN GASEOUS PHASE
Quantity - mole fraction of component in gas mixture
Unit - mol/mol.
Tasks
The main task is the realisation of mole fraction scale for different gas mixtures and its transfer into gas reference materials.
International comparisons
- 1998, CCQM K3, key, CO, CO2, propane in nitrogen
- 2000, EUROMET 485, key, CO, CO2, propane in nitrogen
- 2000, CCQM P23, supplementary, 3 mixtures of CO in nitrogen
- 2001, EUROMET 580, key, ethanol in air
- 2001, CCQM K16, key, natural gas
Available metrological services
- verification tests and type approvals of cehicle exhaust emissions gas analysers
- verification tests and type approvals of breath analysers
- preparation of primary RM of gas mixture for sale
- certification measurement of RM of gas mixtures
Methods of measurement:
Preparation of PRM of gas mixtures is based on keeping the newest ISO standards: ISO 6142 (2001) gas analysis - preparation of calibration gas mixtures - Gravimetric method and ISO 6143 (2001) Gas analysis - determination of the composition of calibration gas mixtures - Comparison methods. Each PRM undergoes validation process in analytical comparison against maintained appropriate set of PRMs at SMU. Cylinders (5 L volume) used for PRMs fulfil the highest requirements for gas mixture stability. SMU provides 2 years stability guarantee for most of its gaseous PRMs. All certification measurements of gas mixtures consist of several automatic comparisons against maintained appropriate set of PRMs at SMU.
Instruments in use
Laboratory is maintaining National standard equipment as collection of filling station, balances, NDIR analyzers, gas chromatographs, FTIR spectrometer, autosamplers, roller and set of PRMs of gas mixtures.
Contact
Mrs. Miroslava Vaľková
phone: +421 2 60294 211
valkova@smu.gov.sk
Dr. Viliam Štovčík
phone: +421 2 60294 523
stovcik@smu.gov.sk
Dr. Beáta Cséfalvayová
phone: +421 2 60294 230
csefalvayova@smu.gov.sk
Dr. Zuzana Ďurišová
phone: +421 2 60294 191
durisova@smu.gov.sk
--------------------------------------------------------------------------------
2. AIR HUMIDITY
Quantity - dewpoint temperature and relative humidity.
Unit - °C for dewpoint temperature; % for relative humidity.
Tasks
The main task is the realisation of dewpoint temperature and relative humidity scale.
International comparisons
The standard instrument is traceable directly to the national standard of National Physical Laboratory, U.K.
Available metrological services
Calibration of dew point temperature instruments based on different measurement principles in the range from -70°C to +20°C laboratory conditions (mirror, capacitance, resistant, etc.). Calibration of relative humidity hydrometers based on different measurement principles in the range from 0 % to 95 % (mechanical, capacitance, resistant, etc.)
Methods of measurement:
- mirror dewpointmeter is used for reproduction of quantities dewpoint temperature (°C) and by calibration of instrument with other dewpointmeters of the other countries.
The Laboratory performances of theoretical workshop with practical training for workers in the field of air-conditioning and cooling techniques, compressors and others.
Instruments in use
Working range: -75°C to +20°C of dewpoint temperature; 0 to 95% relative humidity. Accuracy: U = +- (0.4 to 0.11)°C dewpoint temperature; U = +- (0.4 to 1.2)% relative humidity.
Part of humidity standard is also climate chamber Vötsch VC 4018 with relative humidity range 10 to 98% and extended uncertainty 2%rh (k=2).
Contact
Mrs. Alexandra Kalivodová
phone: +421 2 60294 229
kalivodova@smu.gov.sk
SPECTRAL TRANSMITTANCE LABORATORY
Quantity - Spectral Transmittance and Absorbance at a particular Wavelength.
Unit - 1.
Tasks of the laboratory
The main task of the laboratory is the realisation of Spectral Transmittance and Absorbance scales.
International comparisons
International equivalence of the primary standard equipment was substantiated by bilateral comparison measurements with LNE (France), multirateral comparison measurements organised by SMU within project COOMET 138/SK/96 (GUM PL, UkrCSM UA, CESM BY, VNIIM RU). Multilateral key comparison measurements organised by BIPM within the project CCPR K-6 (NIST USA, NPL U.K., PTB Germany, HUT Finland, MSL New Zeland, etc.) is in evaluation stage.
Available metrological services
Certified reference materials (CMRs) for UV-VIS molecular absorption spectrometers calibration. Calibration of spectrometric cuvettes and of optical filtres for UV-VIS spectrometry.
Methods of measurement:
- calibration of the CRMs performed on the spectral transmittance primary standard equipment
- calibration of the spectrometric cuvettes realised on the primary standard equipment;
- calibration of the optical filtres performed on the primary standard equipment;
- traceability of the spectral trasmittance measuring instruments (UV-VIS molecular absorption spectrometers) used in practice, is assured by means of the CRM set.
Instruments in use
The Spectral Transmittance primary standard equipment is based on commercially produced UV-VIS molecular absorption spectrometers Varian Cary 4E (USA), equipped by wavelength scale (175nm - 900 nm range) and changeable spectral slitwidth (in range from 0.1 nm to 5.0 nm). Standard fused quartz cuvette NIST SRM 932 with inner pathlength (1.00000 ± 0.00005) cm is integral part of primary standard equipment.
Contact
Mrs. Marta Obenrauchová
phone: + 421 2 60294 228
e-mail: obenrauchova@smu.gov.sk
Dr. Viliam Pätoprstý
phone: + 421 2 60294 285
e-mail: patoprsty@smu.gov.sk
REFRACTOMETRY LABORATORY
Quantity - refractive index.
Unit - dimensionless quantity.
Tasks of the laboratory
The main task of the Laboratory is maintenance of the national Standard on the primary level, verification and calibration of working instruments, calibration of working instruments, calibration of optical glass standards and reference materials.
International comparisons
1982 and 1986 bilateral comparisons with PTB, Germany.
1992 bilateral comparison with GUM, Poland.
Since 1999 international comparison among 15 institutions from 11 countries - pilot laboratory PTB, Germany.
Available metrological services
Calibration and verification of visual and digital refractometers (combined standard uncertainty: from 10-5 to 10-4). Refractive index measurement of reference materials (combined standard uncertainty: from 3 x 10-5). refractive index measurement of optical glass prisms (combined standard uncertainty: from 10-6). A measurand level or range for all services: from 1.33 to 1.85.
Methods of measurement:
A basic method of primary measurements on the spectrogoniometer is a method of the deviation. A method of a collimated light beam deviation in V-block of the Pulfrich refractometer PR-2 to its calibration as well as to reference materials calibration is used.
Supplementary activities
There is a possible of measurements of optical prosms angels and cube corner reflectors.
Measurements of a liquid refractive index temperature dependence as well as optical glass prisms within the temperature range (15 - 60)°C by Pulfrich refractometer is possible.
Instuments in use
The Refractive index primary standard (National Standard) of Transparent solid states in visible region consists of the Spectrogoniometer ASKANIA and two standard prisms. It is installed in an air-conditioned laboratory with a temperature control (20.0 ± 1)°C and the floor isolation. For liquid refractive index measurements the device is equipped with a hollow prism with a refractive angle of 60°. The Pulfrich refractometer PR-2 with temperature stabilized V-block as a working standard of the first order for liquid refractive index measurements is used. it is traceable to the primary standard by a set of working standards (8 optical glass prisms) of the primary standard order.
Contact
Dr. Beata Csefalvayova
phone: + 421 2 60294 230
e-mail: csefalvayova@smu.gov.sk
