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.

## SearchCompliance

• ### PCAOB (Public Company Accounting Oversight Board)

The Public Company Accounting Oversight Board (PCAOB) is a Congressionally-established nonprofit that assesses audits of public ...

• ### cyborg anthropologist

A cyborg anthropologist is an individual who studies the interaction between humans and technology, observing how technology can ...

• ### RegTech

RegTech, or regulatory technology, is a term used to describe technology that is used to help streamline the process of ...

## SearchSecurity

• ### email spam

Email spam, or junk email, is unsolicited bulk messages sent through email with commercial, fraudulent or malicious intent.

• ### distributed denial of service (DDoS) attack

A distributed denial-of-service attack occurs when an attack originates from multiple computers or devices, usually from multiple...

• ### application whitelisting

Application whitelisting is the practice of identifying applications that have been deemed safe for execution and restricting all...

## SearchHealthIT

• ### athenahealth Inc.

Based in Watertown, Mass., athenahealth Inc. is a leading vendor of cloud-based EHRs for small to medium-sized physician ...

• ### Affordable Care Act (ACA or Obamacare)

The Affordable Care Act (ACA) is legislation passed in 2010 that changed how uninsured Americans enroll in and receive healthcare...

• ### HIPAA Privacy Rule

The Standards for Privacy of Individually Identifiable Health Information, commonly known as the HIPAA Privacy Rule, establishes ...

## SearchDisasterRecovery

• ### disaster recovery as a service (DRaaS)

One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

• ### data recovery

Data recovery restores data that has been lost, accidentally deleted, corrupted or made inaccessible. Learn how data recovery ...

• ### disaster recovery plan (DRP)

A company's disaster recovery policy is enhanced with a documented DR plan that formulates strategies, and outlines preparation ...

## SearchStorage

• ### yottabyte (YB)

A yottabyte is a measure of theoretical storage capacity and is 2 to the 80th power bytes, or, in decimal, approximately 1,000 ...

• ### Kilo, mega, giga, tera, peta, exa, zetta and all that

Kilo, mega, giga, tera, peta, exa, zetta are among the list of prefixes used to denote the quantity of something, such as a byte ...

• ### brontobyte

A brontobyte is a measure of memory or data storage that is equal to 10 to the 27th power of bytes.

## SearchSolidStateStorage

• ### SSD caching

SSD caching, also known as flash caching, is the temporary storage of data on NAND flash memory chips in a solid-state drive so ...

• ### NVDIMM (Non-Volatile Dual In-line Memory Module)

An NVDIMM (non-volatile dual in-line memory module) is hybrid computer memory that retains data during a service outage.

• ### NAND mirroring

NAND mirroring has been proposed to break the security in certain portable devices that use NAND flash memory for encryption.

## SearchCloudStorage

• ### RESTful API

A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

• ### cloud storage infrastructure

Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

• ### Zadara VPSA and ZIOS

Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close