Path length
Encyclopedia
In chemistry
, the path length is defined as the distance that light (UV/VIS
) travels through a sample in an analytical cell. Typically, a sample cell is made of quartz
, glass, or a plastic rhombic cuvette
with a volume typically ranging from 0.1 mL to 10 mL or larger used in a spectrophotometer. For the purposes of spectrophotometry (i.e. when making calculations using the Beer-Lambert law
) the path length is measured in centimeters (rather than in meters).
In a computer network
, the path length is one of many possible router metrics
used by a router to help determine the best route
among multiple routes to a destination. It consists of the end-to-end hop count
from a source to a destination over the network.
More simply, in general computer terminology, it can mean simply the total number of instructions executed from point A to point B in a program - Instruction path length
.
In physics, the path length is defined as the total distance an object travels. Unlike displacement, which is the total distance an object travels from a starting point, path length is the total distance travelled, regardless of where it travelled.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, the path length is defined as the distance that light (UV/VIS
Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...
) travels through a sample in an analytical cell. Typically, a sample cell is made of quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
, glass, or a plastic rhombic cuvette
Cuvette
A cuvette is a small tube of circular or square cross section, sealed at one end, made of plastic, glass, or fused quartz and designed to hold samples for spectroscopic experiments. The best cuvettes are as clear as possible, without impurities that might affect a spectroscopic reading...
with a volume typically ranging from 0.1 mL to 10 mL or larger used in a spectrophotometer. For the purposes of spectrophotometry (i.e. when making calculations using the Beer-Lambert law
Beer-Lambert law
In optics, the Beer–Lambert law, also known as Beer's law or the Lambert–Beer law or the Beer–Lambert–Bouguer law relates the absorption of light to the properties of the material through which the light is travelling.-Equations:The law states that there is a logarithmic dependence between the...
) the path length is measured in centimeters (rather than in meters).
In a computer network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
, the path length is one of many possible router metrics
Router metrics
Router metrics are metrics used by a router to make routing decisions. It is typically one of many fields in a routing table.Router metrics can contain any number of values that help the router determine the best route among multiple routes to a destination...
used by a router to help determine the best route
Routing
Routing is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...
among multiple routes to a destination. It consists of the end-to-end hop count
Hop count
In computer networking, hop count refers to the number of routers through which data must pass between source and destination. Each router along the data path constitutes a hop, as the data is moved from one Layer 3 network to another...
from a source to a destination over the network.
More simply, in general computer terminology, it can mean simply the total number of instructions executed from point A to point B in a program - Instruction path length
Instruction path length
In computer performance, the instruction path length is the number of machine code instructions required to execute a section of a computer program. The total path length for the entire program could be deemed a measure of the algorithm's performance on a particular computer hardware...
.
In physics, the path length is defined as the total distance an object travels. Unlike displacement, which is the total distance an object travels from a starting point, path length is the total distance travelled, regardless of where it travelled.