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Lux Meter Principle Pdf Download
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Willa Stovel
Dec 6, 2023, 10:01:44 PM12/6/23
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Dr.Meter
The Digital Light meters are used in the fields of cinematography and scenic design, in order to determine the optimum light level for a scene. They are used in the general field of lighting, where they can help to reduce the amount of waste light used in the home, light pollution outdoors, and plant growing to ensure proper light levels
lux meter principle pdf download
DOWNLOAD https://t.co/0u2TF8rIpE
if(typeof ez_ad_units != 'undefined')ez_ad_units.push([[300,250],'yourelectricalguide_com-box-3','ezslot_4',147,'0','0']);__ez_fad_position('div-gpt-ad-yourelectricalguide_com-box-3-0');Hi friends, in this article, I am going to discuss about the lux meter working principle and its application.
We have to measure light in many tasks. For this, the Lux meter should be used. To measure the light accurately, a lux meter is a very suitable device. It is calibrated to read directly in lux.
The meters measure illumination in terms of luxes or foot-candles are known as Lux meters or Light meters.
A lux is equal to the total intensity of light that falls on a one square meter surface that is one foot away from the point of source of light.
A foot-candle is equal to the total intensity of light that falls on a one square foot surface that is one foot away from the point source of light.
Most of the lux meters consist of a body, photocell or light sensor, and display. The light that falls on to the photocell or sensor contains energy that is converted to electric current. In turn, the amount of current depends on the light that strokes the photocell or light sensor. Lux meters read the electrical current, calculate the appropriate value, and shows this value on its display.
It is the basic lux meter working principle. Analog luxmeters display values on a dial usually with a needle or pointer whereas digital devices display values as numbers letters. A Lux meter may be portable or bench type.
Since light usually contains different colors different wavelengths, the reading represents the combined effects of all the wavelengths. Typically, standard colors or color temperatures are expressed in degrees Kelvin (K). The standard color temperature for the calibration of most lux meters is 2856K, an amount that is more yellow than pure white.
Selecting luxmeters or light meters requires certain performance specifications include photocell, illumination range, Lux resolution, operating temperature and foot candle resolution. Special features include low battery Indicators, low voltage, alarms, remote light sensors, built-in memory, auto power off, zero function etc.
The luminous flux falling on a surface per unit area is known as illumination and is expressed in lux. It is also expressed in lumens per square feet.
Lux or Metre Candle: It is defined as the illumination produced by a uniform source of 1 C.P. on the inner surface of a sphere of 1-meter radius.
Foot Candle or Lumens / Sq. Foot: It is defined as the illumination produced by a uniform source of 1 C.P. on the inner surface of a sphere of 1-meter radius.
1 Foot Candle = 10.7608 Lux
1 Lux = 0.09293 ft. Candle
For practical purposes, illumination in lux may be divided by 10 to obtain illumination in lumens/square foot. An idea of illumination levels can be had from the following data:
if(typeof ez_ad_units != 'undefined')ez_ad_units.push([[336,280],'yourelectricalguide_com-large-mobile-banner-1','ezslot_3',151,'0','0']);__ez_fad_position('div-gpt-ad-yourelectricalguide_com-large-mobile-banner-1-0');Illumination requirement in a room depends upon its type and use. For example, in a bathroom, it is 100 lux whereas in a study room it is 300 lux. Because in a study room we need more illumination to read and write properly. You can measure the illumination level in a room at a particular place with the help of a lux meter and increase or decrease the number of light sources ( CFL or LED) accordingly.
Average illumination over a large area is measured by subdividing the whole area into small zones and measuring the illumination at the center of each zone. The dimensions of this area should not exceed the height of light fitting from the working place.
Thanks for reading about lux meter working principle.
The Fluke 941 is a handheld luminometer than can measure visible light sent from a variety of light sources, to include fluorescent, metal halide, high pressure sodium, or incandescent lamps. With an extension cord to the light meter and separate display the Fluke 941 provides a handheld tool to accurately measure light in multiple environments. The Fluke 941 is a portable tool that measures light up to 20,000 fc of lux with an accuracy of .01 fc/lux.
IMPORTANT!:
1. To update the firmware of your meter, install the Data Transfer Software first.
2. Please see the Software Guide for installation under the software tab above.
3. Go to the "Update Setting" tab on the screen of Data Transfer Software, and follow the instructions.
NOTE: Depending on the firmware version, the features and functions may be different.
See the Release Note here for firmware version.
Trend Screen has all the same features included in meter plus a large easy to read graph showing the readings over time. The graph can be displayed in bar or line graph format. Trend Tall is used for portrait mode and Trend wide is used for landscape mode. The Y scale of the graph is the measurement data in the programmed calibrated units, amps for uncalibrated sensors, or in percentage. The X scale is the time interval in seconds. The inclusion of the graph reduces the size of the toggle buttons, but does not eliminate any features.
The central wavelength of the reflected component satisfies the Bragg relation: λBragg = 2nΛ, with n the index of refraction and Λ the period of the index of refraction variation of the FBG. Due to the temperature and strain dependence of the parameters n and Λ, the wavelength of the reflected component will also change as function of temperature and/or strain, see Figure 2. This dependency is well known what allows determining the temperature or strain from the reflected FBG wavelength.
Illuminance is the amount of light falling on a surface. The unit of measurement is lux (or lumens per square metre = 10.76 foot candles, fc). A light meter is used to measure it. Readings are taken from several angles and positions.
Luminance is the amount of light reflected from a surface. The unit of measurement is candela per square metre (equals 0.29 foot-lamberts). An illuminance meter is used to measure it. Several measurements are made and averaged. Luminance tables are consulted for reference values.
Contrast is the relationship between the brightness of an object and its background. A luminance meter is used to measure it. The following formula is used to calculate contrast and provides a number between 0 and 1. The average contrast should be above 0.5:
Reflectance is the ratio of light falling on a surface to the light reflected from a surface, expressed as a percentage. A light meter is used to measure it. Reflectance can also be measured using a reflectometer or by comparing the surface of interest with colour chips of known reflectance.
To determine reflectance, the light meter probe is placed on the test surface to measure light falling on the surface. Next, place the probe 5-7 cm away facing the surface to measure the light reflected from the surface. The following formula is used to calculate reflectance:
An optical power meter (OPM) is a device used to measure the power in an optical signal. The term usually refers to a device for testing average power in fiber optic systems. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power meters (can be photodiode sensors or thermopile laser sensors), light meters or lux meters.
A typical optical power meter consists of a calibrated sensor, measuring amplifier and display.The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels.On the display unit, the measured optical power and set wavelength is displayed. Power meters are calibrated using a traceable calibration standard.
A traditional optical power meter responds to a broad spectrum of light, however, the calibration is wavelength dependent. This is not normally an issue, since the test wavelength is usually known, however, it has a couple of drawbacks. Firstly, the user must set the meter to the correct test wavelength, and secondly, if there are other spurious wavelengths present, then wrong readings will result.
Optical power meters are available as stand-alone bench or handheld instruments or combined with other test functions such as an Optical Light Source (OLS), Visual Fault Locator (VFL), or as sub-system in a larger or modular instrument. Commonly, a power meter on its own is used to measure absolute optical power, or used with a matched light source to measure loss.
When combined with a light source, the instrument is called an Optical Loss Test Set, or OLTS, typically used to measure optical power and end-to-end optical loss. More advanced OLTS may incorporate two or more power meters, and so can measure Optical Return Loss. GR-198, Generic Requirements for Hand-Held Stabilized Light Sources, Optical Power Meters, Reflectance Meters, and Optical Loss Test Sets, discusses OLTS equipment in depth.
Alternatively, an Optical Time Domain Reflectometer (OTDR) can measure optical link loss if its markers are set at the terminus points for which the fiber loss is desired. However, this is an indirect measurement. A single-direction measurement may quite inaccurate if there are multiple fibers in a link, since the back-scatter coefficient is variable between fibers. Accuracy can be increased if a bidirectional average is made. GR-196, Generic Requirements for Optical Time Domain Reflectometer (OTDR) Type Equipment, discusses OTDR equipment in depth.
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The Digital Light meters are used in the fields of cinematography and scenic design, in order to determine the optimum light level for a scene. They are used in the general field of lighting, where they can help to reduce the amount of waste light used in the home, light pollution outdoors, and plant growing to ensure proper light levels
lux meter principle pdf download
DOWNLOAD https://t.co/0u2TF8rIpE
if(typeof ez_ad_units != 'undefined')ez_ad_units.push([[300,250],'yourelectricalguide_com-box-3','ezslot_4',147,'0','0']);__ez_fad_position('div-gpt-ad-yourelectricalguide_com-box-3-0');Hi friends, in this article, I am going to discuss about the lux meter working principle and its application.
We have to measure light in many tasks. For this, the Lux meter should be used. To measure the light accurately, a lux meter is a very suitable device. It is calibrated to read directly in lux.
The meters measure illumination in terms of luxes or foot-candles are known as Lux meters or Light meters.
A lux is equal to the total intensity of light that falls on a one square meter surface that is one foot away from the point of source of light.
A foot-candle is equal to the total intensity of light that falls on a one square foot surface that is one foot away from the point source of light.
Most of the lux meters consist of a body, photocell or light sensor, and display. The light that falls on to the photocell or sensor contains energy that is converted to electric current. In turn, the amount of current depends on the light that strokes the photocell or light sensor. Lux meters read the electrical current, calculate the appropriate value, and shows this value on its display.
It is the basic lux meter working principle. Analog luxmeters display values on a dial usually with a needle or pointer whereas digital devices display values as numbers letters. A Lux meter may be portable or bench type.
Since light usually contains different colors different wavelengths, the reading represents the combined effects of all the wavelengths. Typically, standard colors or color temperatures are expressed in degrees Kelvin (K). The standard color temperature for the calibration of most lux meters is 2856K, an amount that is more yellow than pure white.
Selecting luxmeters or light meters requires certain performance specifications include photocell, illumination range, Lux resolution, operating temperature and foot candle resolution. Special features include low battery Indicators, low voltage, alarms, remote light sensors, built-in memory, auto power off, zero function etc.
The luminous flux falling on a surface per unit area is known as illumination and is expressed in lux. It is also expressed in lumens per square feet.
Lux or Metre Candle: It is defined as the illumination produced by a uniform source of 1 C.P. on the inner surface of a sphere of 1-meter radius.
Foot Candle or Lumens / Sq. Foot: It is defined as the illumination produced by a uniform source of 1 C.P. on the inner surface of a sphere of 1-meter radius.
1 Foot Candle = 10.7608 Lux
1 Lux = 0.09293 ft. Candle
For practical purposes, illumination in lux may be divided by 10 to obtain illumination in lumens/square foot. An idea of illumination levels can be had from the following data:
if(typeof ez_ad_units != 'undefined')ez_ad_units.push([[336,280],'yourelectricalguide_com-large-mobile-banner-1','ezslot_3',151,'0','0']);__ez_fad_position('div-gpt-ad-yourelectricalguide_com-large-mobile-banner-1-0');Illumination requirement in a room depends upon its type and use. For example, in a bathroom, it is 100 lux whereas in a study room it is 300 lux. Because in a study room we need more illumination to read and write properly. You can measure the illumination level in a room at a particular place with the help of a lux meter and increase or decrease the number of light sources ( CFL or LED) accordingly.
Average illumination over a large area is measured by subdividing the whole area into small zones and measuring the illumination at the center of each zone. The dimensions of this area should not exceed the height of light fitting from the working place.
Thanks for reading about lux meter working principle.
The Fluke 941 is a handheld luminometer than can measure visible light sent from a variety of light sources, to include fluorescent, metal halide, high pressure sodium, or incandescent lamps. With an extension cord to the light meter and separate display the Fluke 941 provides a handheld tool to accurately measure light in multiple environments. The Fluke 941 is a portable tool that measures light up to 20,000 fc of lux with an accuracy of .01 fc/lux.
IMPORTANT!:
1. To update the firmware of your meter, install the Data Transfer Software first.
2. Please see the Software Guide for installation under the software tab above.
3. Go to the "Update Setting" tab on the screen of Data Transfer Software, and follow the instructions.
NOTE: Depending on the firmware version, the features and functions may be different.
See the Release Note here for firmware version.
Trend Screen has all the same features included in meter plus a large easy to read graph showing the readings over time. The graph can be displayed in bar or line graph format. Trend Tall is used for portrait mode and Trend wide is used for landscape mode. The Y scale of the graph is the measurement data in the programmed calibrated units, amps for uncalibrated sensors, or in percentage. The X scale is the time interval in seconds. The inclusion of the graph reduces the size of the toggle buttons, but does not eliminate any features.
The central wavelength of the reflected component satisfies the Bragg relation: λBragg = 2nΛ, with n the index of refraction and Λ the period of the index of refraction variation of the FBG. Due to the temperature and strain dependence of the parameters n and Λ, the wavelength of the reflected component will also change as function of temperature and/or strain, see Figure 2. This dependency is well known what allows determining the temperature or strain from the reflected FBG wavelength.
Illuminance is the amount of light falling on a surface. The unit of measurement is lux (or lumens per square metre = 10.76 foot candles, fc). A light meter is used to measure it. Readings are taken from several angles and positions.
Luminance is the amount of light reflected from a surface. The unit of measurement is candela per square metre (equals 0.29 foot-lamberts). An illuminance meter is used to measure it. Several measurements are made and averaged. Luminance tables are consulted for reference values.
Contrast is the relationship between the brightness of an object and its background. A luminance meter is used to measure it. The following formula is used to calculate contrast and provides a number between 0 and 1. The average contrast should be above 0.5:
Reflectance is the ratio of light falling on a surface to the light reflected from a surface, expressed as a percentage. A light meter is used to measure it. Reflectance can also be measured using a reflectometer or by comparing the surface of interest with colour chips of known reflectance.
To determine reflectance, the light meter probe is placed on the test surface to measure light falling on the surface. Next, place the probe 5-7 cm away facing the surface to measure the light reflected from the surface. The following formula is used to calculate reflectance:
An optical power meter (OPM) is a device used to measure the power in an optical signal. The term usually refers to a device for testing average power in fiber optic systems. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power meters (can be photodiode sensors or thermopile laser sensors), light meters or lux meters.
A typical optical power meter consists of a calibrated sensor, measuring amplifier and display.The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels.On the display unit, the measured optical power and set wavelength is displayed. Power meters are calibrated using a traceable calibration standard.
A traditional optical power meter responds to a broad spectrum of light, however, the calibration is wavelength dependent. This is not normally an issue, since the test wavelength is usually known, however, it has a couple of drawbacks. Firstly, the user must set the meter to the correct test wavelength, and secondly, if there are other spurious wavelengths present, then wrong readings will result.
Optical power meters are available as stand-alone bench or handheld instruments or combined with other test functions such as an Optical Light Source (OLS), Visual Fault Locator (VFL), or as sub-system in a larger or modular instrument. Commonly, a power meter on its own is used to measure absolute optical power, or used with a matched light source to measure loss.
When combined with a light source, the instrument is called an Optical Loss Test Set, or OLTS, typically used to measure optical power and end-to-end optical loss. More advanced OLTS may incorporate two or more power meters, and so can measure Optical Return Loss. GR-198, Generic Requirements for Hand-Held Stabilized Light Sources, Optical Power Meters, Reflectance Meters, and Optical Loss Test Sets, discusses OLTS equipment in depth.
Alternatively, an Optical Time Domain Reflectometer (OTDR) can measure optical link loss if its markers are set at the terminus points for which the fiber loss is desired. However, this is an indirect measurement. A single-direction measurement may quite inaccurate if there are multiple fibers in a link, since the back-scatter coefficient is variable between fibers. Accuracy can be increased if a bidirectional average is made. GR-196, Generic Requirements for Optical Time Domain Reflectometer (OTDR) Type Equipment, discusses OTDR equipment in depth.
eebf2c3492
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