Petri Kärhä

  • Otakaari 5

1993 …2020

Tutkimustuotoksia vuodessa

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Tutkimustuotos

Suodatin
Working paper
2014

Characterisation of nonlinearities of array spectroradiometers

Kärhä, P., Nevas, S., Blattner, P., Gawhary, O. E., Pulli, T., Egli, L. & Gröbner, J., 2014, Davos, Switzerland.

Tutkimustuotos: TyöpaperiWorking paperProfessional

High-Resolution Setup for Measuring Photoyellowing of Transparent Materials

Vaskuri, A., Kärhä, P., Mylläri, V., Heikkilä, A. & Ikonen, E., 2014, s. 300-302.

Tutkimustuotos: TyöpaperiWorking paperProfessional

Realization of Improved Solar UV Diffusers

Pulli, T., Schreder, J., Partosoebroto, A., Hülsen, G., Askola, J., Mes, J., Kärhä, P. & Gröbner, J., 2014, Davos, Switzerland.

Tutkimustuotos: TyöpaperiWorking paperProfessional

UVNews - Official Newsletter of the Thematic Network for Ultraviolet Measurement

Kärhä, P., 2014, Espoo, Finland, (UVNews; nro 10).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2013

UVNews - The official Newsletter of the thematic network for ultraviolet measurements

Kärhä, P., 2013, Espoo, (UVNews; nro 9).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2011

Measurement Setups and Methods for UV Action Spectra of Materials

Kärhä, P., Heikkilä, A. & Kaunismaa, M., 2011, s. 136-137.

Tutkimustuotos: TyöpaperiWorking paperProfessional

2010

Prospects in Online Optical Identification of Polymeric Materials Future of Recycling

Hyvönen, T., Ojanen, M., Kärhä, P. & Ikonen, E., 2010, s. 84.

Tutkimustuotos: TyöpaperiWorking paperProfessional

Spectral Irradiance Model for Tungsten Halogen Lamps in 340 850 nm Wavelength Range

Ojanen, M., Kärhä, P. & Ikonen, E., 2010, s. 39.

Tutkimustuotos: TyöpaperiWorking paperProfessional

2009

A multifunctional setup for measurement of LED luminous flux based on integrating sphere method

Poikonen, T., Kärhä, P., Manninen, P. & Ikonen, E., 2009, s. 115116, (the CIE Light and Lighting Conference, Budapest, Hungary, May 2729, 2009, (poster with short oral introduction).).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Applicability of random and biased error models in uncertainty evaluation of photometer quality factor f1

Poikonen, T., Kärhä, P., Manninen, P., Manoocheri, F. & Ikonen, E., 2009, s. 256, (The XLIII annual conference of the Finnish Physical Society, Espoo, Finland, March 1214, 2009).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Determination of LED luminance and radiance from effective intensity

Ikonen, E., Poikonen, T., Kärhä, P. & Manninen, P., 2009, Budapest, Hungary, s. 174175, (The CIE Light and Lighting Conference, Budapest, Hungary, May 2729, 2009).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Driving innovation with nanotechnology and functional materials in Finland

Heikkilä, A., Syrjälä, S., Kärhä, P., Sormanen, A., Naula-Iltanen, A., Kaunismaa, M., Ture, T. & Koskinen, J., 2009, (UVEMA2 - UV radiation effects on materials,” Tekes Annual Seminar “”, May 27-28, 2009, Helsinki, Helsinki Fair Centre, Finland).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Effects of terrestrial UV radiation on selected outdoor materials: an interdisciplinary approach

Heikkilä, A., Kazadzis, S., Tolonen-Kivimäki, O., Meinander, O., Lindfors, A., Lakkala, K., Koskela, T., Kaurola, J., Sormanen, A., Kärhä, P., Naula-Iltanen, A., Syrjälä, S., Kaunismaa, M., Juhola, J., Ture, T., Feister, U., Kouremeti, N., Bais, A., Vilaplana, J. M., Rodriguez, J. J. & 3 muuta, Guirado, C., Cuevas, E. & Koskinen, J., 2009, (SPIE 7462, 74620G (2009)).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Imperfections in UV diffusers: practical consequences

Manninen, P., Koskela, T., Ylianttila, L., Kärhä, P. & Ikonen, E., 2009, (12th Biennial WMO-GAW Brewer Users Group Meeting, Aosta, Italy, 2026 September 2009).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Optical temperature measurement of miniature silicon emitters

Shpak, M., Ojanen, M., Kärhä, P., Ikonen, E., Heinonen, M. & Weckström, T., 2009, s. 285, (The XLIII annual conference of the Finnish Physical Society, Espoo, Finland, March 1214, 2009).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2008

Comparison of the radiation temperature scales between PTB and MIKES

Ojanen, M., Anhalt, K., Hartmann, J., Weckström, T., Kärhä, P., Heinonen, M. & Ikonen, E., 2008, s. 285-286, (The 10th international conference on New Developments and Applications in Optical Radiometry (NEWRAD 2008), Daejeon, South-Korea, October 13-16, 2008).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Luminous flux measurement of light emitting diodes

Poikonen, T., Manninen, P., Kärhä, P. & Ikonen, E., 2008, (The XXXXII Annual Conference of the Finnish Physical Society 2008, Turku, Finland, 2729 March, 2008).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Outdoor weathering of glass fibre reinforced polyester and vinyl ester composites: first results after one year exposure

Kärhä, P., Heikkilä, A., Juhola, J., Kaunismaa, M., Hakkarainen, J., Meinander, O., Tolonen-Kivimäki, O., Feister, U., Kazadzis, S., Bais, A., Guerrero, J. M. V., Guirado, C., Rodríguez, J., Ture, T., Syrjälä, S. & Koskinen, J., 2008, (13th European Conference on Composite Materials (ECCM13), 2-5 Jun 2008, Stockholm, Sweden).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Towards life-time estimations for outdoor polymeric materials in the changing climate”

Kärhä, P., Heikkilä, A., Meinander, O., Tolonen-Kivimäki, O., Lindfors, A., Kaurola, J., Koskela, T., Lakkala, K., Naula-Iltanen, A., Sormanen, A., Juhola, J., Kaunismaa, M., Feister, U., Puglisi, N., Dell’Acqua, A., Verdebout, J., Putaud, J-P., Kouremeti, N., Kazadzis, S., Bais, A. & 6 muuta, Guerrero, J. M. V., Guirado, C., Rodríguez, J., Ture, T., Syrjälä, S. & Koskinen, J., 2008, (ESF/FMHS Entre-Sciences Conference New methodologies and Interdisciplinary Approaches in Global Change Research", 5-10 November 2008, IGeSA, Porquerolles, France).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2007

Facility for spectral ultraviolet aging of materials

Kärhä, P., Ruokolainen, K. & Heikkilä, A., 2007, s. 286, (XLI Annual Conference of the Finnish Physical Society, Tallinn, Estonia, March 15-18, 2007).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Quantification of material exposure to ultraviolet radiation

Heikkilä, A., Tanskanen, A., Lindfors, A., Kärhä, P. & Syrjälä, S., 2007, s. 461-470, (3rd European Weathering Symposium, Krakow, Poland, September 12-14, 2007).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2006

Analysis of luminous intensity of light emitting diodes with modified inverse square law

Manninen, P., Hovila, J., Kärhä, P. & Ikonen, E., 2006, s. 124, (Northern Optics 2006, Bergen, Norway, June 14-16, 2006).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Calibration of broadband ultraviolet detectors by measurement of spectral irradiance responsivity

Envall, J., Kärhä, P. & Ikonen, E., 2006, Espoo, (Metrology Research Institute Report; nro 30/2006).

Tutkimustuotos: TyöpaperiWorking paperProfessional

3 Sitaatiot (Scopus)

Distance offset of the effective receiving aperture of a diffuser and its relation to angular responsivity curves

Manninen, P., Hovila, J., Kärhä, P., Ylianttila, L. & Ikonen, E., 2006, s. 125, (Northern Optics 2006, Bergen, Norway, June 14-16, 2006).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Polarization properties of GaAsP trap detectors

Sildoja, M-M., Kübarsepp, T., Noorma, M., Kärhä, P., Lamminpää, A., Nevas, S. & Ikonen, E., 2006, s. 95-96, (Estonian Physics Society, Tallinn, Estonia, March 21-22, 2006).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Scale realization of high fiber optic power

Lamminpää, A., Hieta, T., Envall, J., Kärhä, P. & Ikonen, E., 2006, s. 314, (XL Annual Conference of the Finnish Physical Society, Tampere, Finland, March 9-11, 2006).

Tutkimustuotos: TyöpaperiWorking paperProfessional

UVNews

Kärhä, P., 2006, Espoo, s. 63, (UVNews, The official newsletter of the Thematic Network for Ultraviolet Measurements; nro 8).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2005

Analysis of the uncertainty propagation through fitting spectral irradiance data

Nevas, S., Lamminpää, A., Kärhä, P. & Ikonen, E., 2005, s. 263-264, (9th International Conference on New Developments and Applications in Optical Radiometry, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Calibration of broadband ultraviolet detectors by measurement of spectral irradiance responsivity

Envall, J., Kärhä, P. & Ikonen, E., 2005, s. 387, (The XXXIX Annual Conference of the Finnish Physical Society, Espoo, Finland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

3 Sitaatiot (Scopus)

Calibration of current-to-voltage converters for radiometric applications at picoampere level

Sipilä, P., Rajala, R., Kärhä, P., Manninen, P. & Ikonen, E., 2005, s. 223-224, (9th International Conference on New Developments and Applications in Optical Radiometry, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Comparison of spectral irradiance responsivity scales of TKK and NIST in the UVA region

Envall, J., Johnson, C., Kärhä, P., Larason, T. & Ikonen, E., 2005, s. 147-148, (9th International Conference on New Developments and Applications in Optical Radiometry, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Determination of reference planes of spectroradiometer diffusers

Kärhä, P., Hovila, J., Manninen, P., Seppälä, L., Ylianttila, L. & Ikonen, E., 2005, s. 48, (6th Workshop on Ultraviolet Radiation Measurements, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Determination of the diffuser reference plane for accurate photometric and radiometric measurements

Hovila, J., Manninen, P., Seppälä, L., Kärhä, P., Ylianttila, L. & Ikonen, E., 2005, s. 201-202, (9th International Conference on New Developments and Applications in Optical Radiometry, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

GaAsP photodiodes and trap detector for high accuracy measurements in ultraviolet wavelength region

Lamminpää, A., Noorma, M., Nevas, S., Manoocheri, F., Kärhä, P. & Ikonen, E., 2005, s. 388, (The XXXIX Annual Cinference of the Finnish Physical Society, Espoo, Finland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Opinnäytetyön ohjaus Teknillisessä korkeakoulussa

Kärhä, P., Hollmen, J., Karling, S., Kujala, J., Kuosmanen, P. & Lindqvist, J., 2005, Espoo, s. 38, (Metrology Research Institute Report; nro Report 28/2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Photometry of light emitting diodes

Manninen, P., Hovila, J., Kärhä, P. & Ikonen, E., 2005, s. 375, (The XXXIX Annual Conference of the Finnish Physical Society, Espoo, Finland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Polarization sensivity of GaAsP photodetectors

Sildoja, M-M., Kübarsepp, T., Noorma, M., Kärhä, P., Lamminpää, A., Nevas, S. & Ikonen, E., 2005, s. 59, (Optics Days 2005, Jyväskylä, Finland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Radiometric temperature measurements with absolutely characterized filter radiometers in irradiance mode

Noorma, M., Ahtee, V., Lamminpää, A., Kärhä, P., Manoocheri, F., Weckström, T. & Ikonen, E., 2005, Espoo, s. 11, (Metrology Research Institute Report; nro 24/2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Results and experiences from high fibre optic power calibration comparison

Andersson, A., Envall, J., Kärhä, P., Ikonen, E. & Petersen, J., 2005, s. 6, (12th International Metrology Congress, Lyon, France, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

UVEMA: A new project exploring degrading effects of UV radiation on materials

Heikkilä, A., Hanhi, K., Kaurola, J., Koskela, T., Koskinen, J., Kärhä, P., Tanskanen, A. & Ture, T., 2005, s. 38, (6th Workshop on Ultraviolet Radiation Measurements, Davos, Switzerland, 2005).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2004

Special application of photometry: Calibration of a photometer measuring mari-time LED buoy lanterns

Hovila, J., Kärhä, P., Mansner, L. & Ikonen, E., 2004, (Optics Days 2004, Turku, May 6-7, 2004).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2003

Annual Report 2002, Metrology Research Institute

Kärhä, P., 2003, Espoo, (Metrology Research Institute Report; nro 21/2003).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Detector based method for radiations temperature measurements

Jankowski, T., Kärhä, P., Noorma, M., Weckström, T., Uusipaikka, L. & Ikonen, E., 2003, Espoo, (Northern Optics 2003, Espoo, June 16-18).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Instabilities in the areas of precision apertures

Noorma, M., Kärhä, P. & Ikonen, E., 2003, Espoo, (Northern Optics 2003, Espoo, June 16-18).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Systematic change in areas of the aperture used in optical radiometry

Noorma, M., Kärhä, P. & Ikonen, E., 2003, Tartu, Estonia, s. 74-75, (Estonian Physics Days, Tartu, Estonia, February 14-15).

Tutkimustuotos: TyöpaperiWorking paperProfessional

2002

Ageing of DXW-lamps

Ylianttila, L., Jokela, K. & Kärhä, P., 2002, USA, s. 119, (NEWRAD2002, Gaithersburg, USA, May 20-24, 2002).

Tutkimustuotos: TyöpaperiWorking paperProfessional

4 Sitaatiot (Scopus)

Annual Report 2001

Kärhä, P., 2002, Espoo, Finland, s. 64, (Metrology Research Institute Report; nro 20).

Tutkimustuotos: TyöpaperiWorking paperProfessional

A portable field calibrator for solar ultraviolet measurements

Kärhä, P., Ylianttila, L., Jokela, K. & Ikonen, E., 2002, s. 16-17, (5th Workshop on Ultraviolet Radiation Measurements, Kassandra, Halkidiki, Greece, October 7-8, 2002).

Tutkimustuotos: TyöpaperiWorking paperProfessional

Comparison measurements of spectral irradiance between NIST and HUT

Kübarsepp, T., Yoon, H. W., Nevas, S., Kärhä, P. & Ikonen, E., 2002, USA, s. 102, (NEWRAD2002, Gaithersburg, USA, May 20-24, 2002).

Tutkimustuotos: TyöpaperiWorking paperProfessional

High-intensity setup for measuring spectral irradiance responsivities of UV meters

Envall, J., Kärhä, P. & Ikonen, E., 2002, s. 18-19, (5th Workshop on Ultraviolet Radiation Measurements, Kassandra, Halkidiki, Greece, October 7-8, 2002).

Tutkimustuotos: TyöpaperiWorking paperProfessional