Browse Definitions :
Definition

lux (lx)

The lux (symbolized lx) is the unit of illuminance in the International System of Units ( SI ). It is defined in terms of lumen s per meter squared (lm/m 2 ). Reduced to SI base units, one lux is equal to 0.00146 kilogram per second cubed (1.46 x 10 -3 kg / s 3 ).

One lux is the equivalent of 1.46 milliwatt (1.46 x 10 -3 W) of radiant electromagnetic (EM) power at a frequency of 540 terahertz (540 THz or 5.40 x 10 14 Hz ), impinging at a right angle on a surface whose area is one square meter. A frequency of 540 THz corresponds to a wavelength of about 555 nanometer s (nm), which is in the middle of the visible-light spectrum.

The lux is a small unit. An alternative unit is the watt per meter squared (W / m 2 ). To obtain lux when the illuminance in watts per meter squared is known, multiply by 683. To obtain watts per meter squared when the illuminance in lux is known, divide by 683 or multiply by 0.00146.

Illuminance varies inversely with the square of the distance from the source on a free-space line of sight. If the distance is doubled, the illuminance is cut to 1/4; if the distance increases by a factor of 10, the illuminance becomes 1/100 (0.01 times) as great.

Also see candela , electromagnetic field , lumen , steradian , watt per meter squared , and International System of Units ( SI ).

This was last updated in March 2011

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • compliance audit

    A compliance audit is a comprehensive review of an organization's adherence to regulatory guidelines.

  • regulatory compliance

    Regulatory compliance is an organization's adherence to laws, regulations, guidelines and specifications relevant to its business...

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

SearchSecurity

  • brute force attack

    Brute force (also known as brute force cracking) is a trial and error method used by application programs to decode encrypted ...

  • spyware

    Spyware is software that is installed on a computing device without the user's knowledge. Spyware can be difficult to detect; ...

  • ATM black box attack

    An ATM black box attack, also referred to as jackpotting, is a type of banking-system crime in which the perpetrators bore holes ...

SearchHealthIT

SearchDisasterRecovery

  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • warm site

    A warm site is a type of facility an organization uses to recover its technology infrastructure when its primary data center goes...

  • disaster recovery (DR) test

    A disaster recovery test (DR test) is the examination of each step in a disaster recovery plan as outlined in an organization's ...

SearchStorage

  • enterprise storage

    Enterprise storage is a centralized repository for business information that provides common data management, protection and data...

  • disk array

    A disk array, also called a storage array, is a data storage system used for block-based storage, file-based storage or object ...

  • optical storage

    Optical storage is any storage type in which data is written and read with a laser. Typically, data is written to optical media, ...

Close