Die Farbwiedergabeeigenschaften einer Lichtquelle lassen sich durch den allgemeined Farbwiedergab... more Die Farbwiedergabeeigenschaften einer Lichtquelle lassen sich durch den allgemeined Farbwiedergabe-Index R3 charakterisieren. Für diesen Artikel wurde die Anzahl der gebundenen Farben erhöht. Die Farbabgleichabweichun- gen (colour mismatch) werden als Verschiebungen in Buntton und in Bunt- heit getrennt für eine größere Farbengruppe vorgeführt. Es stellt sich heraus, daß die Abweichungen im Farbabgleich für Buntton und Buntheit ziemlich gleichmäßige Funktionen des Bunttons, der prhnären Eigenschaft zur Einteilung der Farben, sind. Dies führt zu der Möglichkeit, für eine gewisse Anwendung die alternati- ven Lichtquefllen entweder über den gesamten Farbenraum oder über einen für die Anwendung wesentlichen Teil davon zu vergleichen. Dieser Ver- gleich kann auf Annehmbarkeit oder auch auf Bevorzugümg gegründet werden. Ergebnisse dieser Verfahrensweise werden für eine Anzahl Nieder- druck-Leuchtstofflampen und für einige Hochdruck-Endladungslampen gegeben werden
A number of studies concerning the preference of people for specific luminance distribution in of... more A number of studies concerning the preference of people for specific luminance distribution in offices aimed at the effects of different lighting modes. In the analysis of the data the emphasis was focused on the average appreciation of the observers to derive the optimum conditions obtainable with fixed lighting conditions. This is well motivated as the availability of switching and dimming systems to individualise the luminous environment to tasks and personal preferences was not widespread. The rapid growth of electronic controls for fluorescent lighting urges for a investigation towards the distribution of preferences for luminance contrast amongst the office population. The results will be reported of a study in which a large sample of office workers judged luminance contrasts between task and surroundings under the exclusion of daylight. Subjects did adjust the lighting conditions to obtain maximum satisfaction. In the study both local and general diffuse lighting conditions w...
ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering ... more ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering properties of light sources. Being a single number the CRI is a comprehensible figure of merit. The accuracy of the CRI in predicting specific colour rendering aspects is relatively low. CRI is an average of only 8 colours and accounts only for the size of the colour shift. Several new suggestions for an improved description of colour rendering have been done. All these suggestions had one thing in common: the description of colour rendering gets more complicated. In this paper we will present a new way of analysing colour shifts and discuss the effect of the colour sets and the effect of narrow band spectral power distributions on the accuracy and simplicity of colour rendering information.
This paper describes our methods of supplying hue specific information via color rendering vector... more This paper describes our methods of supplying hue specific information via color rendering vectors and color rendering icons. We illustrate why we believe it is important to add hue specific information and the shortcomings of a second hue-averaged metric.
ABSTRACT A new generation of Special de Luxe fluorescent lamps with a diameter of 26 mm (T8, TLD)... more ABSTRACT A new generation of Special de Luxe fluorescent lamps with a diameter of 26 mm (T8, TLD) has been produced; These new lamps with colour temperatures between 2600 K and $000 K combine excellent colour rendering properties with a high efficacy and good maintenance. 'R1ese new lamps are made with a blend of recently developed new phosphors. The efficacy of 62-66 1m/Watt of the 36 Watt versions with Ra values of about 95 gives a gain of 30-45. Z in efficacy over the existing 40 Watt TL lamps with the same co1our—rendering properties.
Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary i... more Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.
ost descriptions of the colour rendering properties of light sources are based on the calculation... more ost descriptions of the colour rendering properties of light sources are based on the calculation of colour differences for a number of test colours between the light source and a reference source. The CIE colourrendering index CRI is a single number based on the average colour difference for 8 test colours. In the past several suggestions have been made to improve the description of the colour-rendering index such as colour preference index, colour appearance data and colour discrimination index. The drive for improvement of the description of colour rendering seems to be contradictory with the requirement of expressing the colour rendering properties in a comprehensible and simple way. More accurate colour description can be reached by increasing the number of test colours and by considering both the magnitude and direction of the colour differences for each individual test colour. This however significantly increases the amount of information, which needs to be communicated. With...
This paper presents an overview of available compact light sources and discusses the latest techn... more This paper presents an overview of available compact light sources and discusses the latest technologies in halogen and compact metal halide discharge light sources. A new selection tool for accent light sources will be presented.
Artificial outdoor lighting plays several important roles. In addition to functional roles such a... more Artificial outdoor lighting plays several important roles. In addition to functional roles such as improving visibility and providing orientation, outdoor lighting is increasingly required to contribute to the lifestyle and feeling of emotional well-being of people outside at night. In this regard, outdoor lighting can help to increase the feeling of safety and security among pedestrians, as well as to enhance the attractiveness, ambience and appearance of an illuminated area. Environmentally, it is desirable to use efficient light sources with good optical control so that the targeted area is efficiently illuminated while sky glow and unwanted stray light are minimized. At present, high-pressure sodium (HPS) lamps are widely used in outdoor applications due to their high efficacy and long, reliable lifetime. The use of these lamps however, comes at the expense of good color rendering and accurate color appearance of outdoor spaces. Recently developed ceramic metal halide lamps can ...
ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering ... more ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering properties of light sources. Being a single number the CRI is a comprehensible figure of merit. The accuracy of the CRI in predicting specific colour rendering aspects is relatively low. CRI is an average of only 8 colours and accounts only for the size of the colour shift. Several new suggestions for an improved description of colour rendering have been done. All these suggestions had one thing in common: the description of colour rendering gets more complicated. In this paper we will present a new way of analysing colour shifts and discuss the effect of the colour sets and the effect of narrow band spectral power distributions on the accuracy and simplicity of colour rendering information.
Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimm... more Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimmung von Menschen hat, wird allgemein angenommen, eine quantitative Bewertung fehlt allerdings noch. Um psychologische und physiologische Effekte der Beleuchtung zu untersuchen braucht man Methoden, die möglichst objektiv Ermüdung, Stimmung, Aktivierungsniveau oder Stress messen. Diese Methoden dürfen die Effekte, die sie messen sollen, nicht beeinflussen. Wir haben dazu mehrere psychologischen Tests sowie die Herzschlagvariabilität experimentell auf ihre Brauchbarkeit für die obengenannten Messungen unter verschiedenen Lichtverhältnissen durchgeführt. Von der Herzschlagvariabilität (Schwankungen der Herzfrequenz) ist bekannt dass sie bei größerer geistigen Anstrengung niedriger wird. Diese Experimente und die Brauchbarkeit von den verschiedenen psychologischen Tests und der Herzschlagvariabilität für die Auswertungen von Lichtverhältnissen werden diskutiert.
Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimm... more Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimmung von Menschen hat, wird allgemein angenommen, eine quantitative Bewertung fehlt allerdings noch. Um psychologische und physiologische Effekte der Beleuchtung zu untersuchen braucht man Methoden, die möglichst objektiv Ermüdung, Stimmung, Aktivierungsniveau oder Stress messen. Diese Methoden dürfen die Effekte, die sie messen sollen, nicht beeinflussen. Wir haben dazu mehrere psychologischen Tests sowie die Herzschlagvariabilität experimentell auf ihre Brauchbarkeit für die obengenannten Messungen unter verschiedenen Lichtverhältnissen durchgeführt. Von der Herzschlagvariabilität (Schwankungen der Herzfrequenz) ist bekannt dass sie bei größerer geistigen Anstrengung niedriger wird. Diese Experimente und die Brauchbarkeit von den verschiedenen psychologischen Tests und der Herzschlagvariabilität für die Auswertungen von Lichtverhältnissen werden diskutiert.
Home > Publishers > AIP Publishing > Journal of Applied Physics > Volume 50, Issue 2 > Article ba... more Home > Publishers > AIP Publishing > Journal of Applied Physics > Volume 50, Issue 2 > Article banner image Direct determination of barrier voltage in ZnO varistors J. T. C. van Kemenade1 and R. K. Eijnthoven1 + VIEW AFFILIATIONS J. Appl. Phys. 50, 938 (1979); http://dx.doi.org/10.1063/1.326015 Rent: $4.00 PREVIOUS ARTICLE TABLE OF CONTENTSNEXT ARTICLE facebook twitter Share this page separator email print this page Abstract Full Text References (11) Cited By (58) Data & Media Metrics Related Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.
Die Farbwiedergabeeigenschaften einer Lichtquelle lassen sich durch den allgemeined Farbwiedergab... more Die Farbwiedergabeeigenschaften einer Lichtquelle lassen sich durch den allgemeined Farbwiedergabe-Index R3 charakterisieren. Für diesen Artikel wurde die Anzahl der gebundenen Farben erhöht. Die Farbabgleichabweichun- gen (colour mismatch) werden als Verschiebungen in Buntton und in Bunt- heit getrennt für eine größere Farbengruppe vorgeführt. Es stellt sich heraus, daß die Abweichungen im Farbabgleich für Buntton und Buntheit ziemlich gleichmäßige Funktionen des Bunttons, der prhnären Eigenschaft zur Einteilung der Farben, sind. Dies führt zu der Möglichkeit, für eine gewisse Anwendung die alternati- ven Lichtquefllen entweder über den gesamten Farbenraum oder über einen für die Anwendung wesentlichen Teil davon zu vergleichen. Dieser Ver- gleich kann auf Annehmbarkeit oder auch auf Bevorzugümg gegründet werden. Ergebnisse dieser Verfahrensweise werden für eine Anzahl Nieder- druck-Leuchtstofflampen und für einige Hochdruck-Endladungslampen gegeben werden
A number of studies concerning the preference of people for specific luminance distribution in of... more A number of studies concerning the preference of people for specific luminance distribution in offices aimed at the effects of different lighting modes. In the analysis of the data the emphasis was focused on the average appreciation of the observers to derive the optimum conditions obtainable with fixed lighting conditions. This is well motivated as the availability of switching and dimming systems to individualise the luminous environment to tasks and personal preferences was not widespread. The rapid growth of electronic controls for fluorescent lighting urges for a investigation towards the distribution of preferences for luminance contrast amongst the office population. The results will be reported of a study in which a large sample of office workers judged luminance contrasts between task and surroundings under the exclusion of daylight. Subjects did adjust the lighting conditions to obtain maximum satisfaction. In the study both local and general diffuse lighting conditions w...
ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering ... more ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering properties of light sources. Being a single number the CRI is a comprehensible figure of merit. The accuracy of the CRI in predicting specific colour rendering aspects is relatively low. CRI is an average of only 8 colours and accounts only for the size of the colour shift. Several new suggestions for an improved description of colour rendering have been done. All these suggestions had one thing in common: the description of colour rendering gets more complicated. In this paper we will present a new way of analysing colour shifts and discuss the effect of the colour sets and the effect of narrow band spectral power distributions on the accuracy and simplicity of colour rendering information.
This paper describes our methods of supplying hue specific information via color rendering vector... more This paper describes our methods of supplying hue specific information via color rendering vectors and color rendering icons. We illustrate why we believe it is important to add hue specific information and the shortcomings of a second hue-averaged metric.
ABSTRACT A new generation of Special de Luxe fluorescent lamps with a diameter of 26 mm (T8, TLD)... more ABSTRACT A new generation of Special de Luxe fluorescent lamps with a diameter of 26 mm (T8, TLD) has been produced; These new lamps with colour temperatures between 2600 K and $000 K combine excellent colour rendering properties with a high efficacy and good maintenance. 'R1ese new lamps are made with a blend of recently developed new phosphors. The efficacy of 62-66 1m/Watt of the 36 Watt versions with Ra values of about 95 gives a gain of 30-45. Z in efficacy over the existing 40 Watt TL lamps with the same co1our—rendering properties.
Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary i... more Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.
ost descriptions of the colour rendering properties of light sources are based on the calculation... more ost descriptions of the colour rendering properties of light sources are based on the calculation of colour differences for a number of test colours between the light source and a reference source. The CIE colourrendering index CRI is a single number based on the average colour difference for 8 test colours. In the past several suggestions have been made to improve the description of the colour-rendering index such as colour preference index, colour appearance data and colour discrimination index. The drive for improvement of the description of colour rendering seems to be contradictory with the requirement of expressing the colour rendering properties in a comprehensible and simple way. More accurate colour description can be reached by increasing the number of test colours and by considering both the magnitude and direction of the colour differences for each individual test colour. This however significantly increases the amount of information, which needs to be communicated. With...
This paper presents an overview of available compact light sources and discusses the latest techn... more This paper presents an overview of available compact light sources and discusses the latest technologies in halogen and compact metal halide discharge light sources. A new selection tool for accent light sources will be presented.
Artificial outdoor lighting plays several important roles. In addition to functional roles such a... more Artificial outdoor lighting plays several important roles. In addition to functional roles such as improving visibility and providing orientation, outdoor lighting is increasingly required to contribute to the lifestyle and feeling of emotional well-being of people outside at night. In this regard, outdoor lighting can help to increase the feeling of safety and security among pedestrians, as well as to enhance the attractiveness, ambience and appearance of an illuminated area. Environmentally, it is desirable to use efficient light sources with good optical control so that the targeted area is efficiently illuminated while sky glow and unwanted stray light are minimized. At present, high-pressure sodium (HPS) lamps are widely used in outdoor applications due to their high efficacy and long, reliable lifetime. The use of these lamps however, comes at the expense of good color rendering and accurate color appearance of outdoor spaces. Recently developed ceramic metal halide lamps can ...
ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering ... more ABSTRAC The CIE Colour Rendering Index (CRI) is a well-known descriptor for the colour rendering properties of light sources. Being a single number the CRI is a comprehensible figure of merit. The accuracy of the CRI in predicting specific colour rendering aspects is relatively low. CRI is an average of only 8 colours and accounts only for the size of the colour shift. Several new suggestions for an improved description of colour rendering have been done. All these suggestions had one thing in common: the description of colour rendering gets more complicated. In this paper we will present a new way of analysing colour shifts and discuss the effect of the colour sets and the effect of narrow band spectral power distributions on the accuracy and simplicity of colour rendering information.
Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimm... more Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimmung von Menschen hat, wird allgemein angenommen, eine quantitative Bewertung fehlt allerdings noch. Um psychologische und physiologische Effekte der Beleuchtung zu untersuchen braucht man Methoden, die möglichst objektiv Ermüdung, Stimmung, Aktivierungsniveau oder Stress messen. Diese Methoden dürfen die Effekte, die sie messen sollen, nicht beeinflussen. Wir haben dazu mehrere psychologischen Tests sowie die Herzschlagvariabilität experimentell auf ihre Brauchbarkeit für die obengenannten Messungen unter verschiedenen Lichtverhältnissen durchgeführt. Von der Herzschlagvariabilität (Schwankungen der Herzfrequenz) ist bekannt dass sie bei größerer geistigen Anstrengung niedriger wird. Diese Experimente und die Brauchbarkeit von den verschiedenen psychologischen Tests und der Herzschlagvariabilität für die Auswertungen von Lichtverhältnissen werden diskutiert.
Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimm... more Zusammenfassung Dass Licht einen Einfluss, abgesehen vom Sehen, auf der Arbeitsleistung und Stimmung von Menschen hat, wird allgemein angenommen, eine quantitative Bewertung fehlt allerdings noch. Um psychologische und physiologische Effekte der Beleuchtung zu untersuchen braucht man Methoden, die möglichst objektiv Ermüdung, Stimmung, Aktivierungsniveau oder Stress messen. Diese Methoden dürfen die Effekte, die sie messen sollen, nicht beeinflussen. Wir haben dazu mehrere psychologischen Tests sowie die Herzschlagvariabilität experimentell auf ihre Brauchbarkeit für die obengenannten Messungen unter verschiedenen Lichtverhältnissen durchgeführt. Von der Herzschlagvariabilität (Schwankungen der Herzfrequenz) ist bekannt dass sie bei größerer geistigen Anstrengung niedriger wird. Diese Experimente und die Brauchbarkeit von den verschiedenen psychologischen Tests und der Herzschlagvariabilität für die Auswertungen von Lichtverhältnissen werden diskutiert.
Home > Publishers > AIP Publishing > Journal of Applied Physics > Volume 50, Issue 2 > Article ba... more Home > Publishers > AIP Publishing > Journal of Applied Physics > Volume 50, Issue 2 > Article banner image Direct determination of barrier voltage in ZnO varistors J. T. C. van Kemenade1 and R. K. Eijnthoven1 + VIEW AFFILIATIONS J. Appl. Phys. 50, 938 (1979); http://dx.doi.org/10.1063/1.326015 Rent: $4.00 PREVIOUS ARTICLE TABLE OF CONTENTSNEXT ARTICLE facebook twitter Share this page separator email print this page Abstract Full Text References (11) Cited By (58) Data & Media Metrics Related Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.
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Direct determination of barrier voltage in ZnO varistors
J. T. C. van Kemenade1 and R. K. Eijnthoven1
+ VIEW AFFILIATIONS
J. Appl. Phys. 50, 938 (1979); http://dx.doi.org/10.1063/1.326015
Rent: $4.00
PREVIOUS ARTICLE TABLE OF CONTENTSNEXT ARTICLE facebook twitter Share this page separator email print this page
Abstract
Full Text
References (11)
Cited By (58)
Data & Media
Metrics
Related
Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.
Direct determination of barrier voltage in ZnO varistors
J. T. C. van Kemenade1 and R. K. Eijnthoven1
+ VIEW AFFILIATIONS
J. Appl. Phys. 50, 938 (1979); http://dx.doi.org/10.1063/1.326015
Rent: $4.00
PREVIOUS ARTICLE TABLE OF CONTENTSNEXT ARTICLE facebook twitter Share this page separator email print this page
Abstract
Full Text
References (11)
Cited By (58)
Data & Media
Metrics
Related
Single barriers in a ZnO varistor are measured separately. The step voltage at a grain boundary is 3.6 V at 1 μA. No great differences could be found between samples obtained from several suppliers. In a SEM the barriers could be detected by the voltage‐contrast method. By using electron‐beam‐induced currents the spots where current is flowing may be located.