Info Library

Glossary of Terms > D

Darlington pair

Two transistors connected together so that the current amplified by the first is further amplified by the second transistor, giving a very high gain.

Data

Facts in the form of values given by a test instrument or otherwise gathered through scientific investigation.

Dataloggers

A device which gathers environmental data via sensors. This data can then be uploaded to a computer or otherwise manipulated by the user.

Density

Mass per unit of volume

Diffraction

The bending of light around objects, such as cloud and fog droplets, producing fringes of light and dark or colored bands.

Diffraction grating

A series of thousands of parallel lines etched onto glass, used to diffract light in spectra experiments.

Diode

An electronic component that allows current to flow in only one direction.

DNA

Short for Deoxy-Ribonucleic Acid; makes up the genetic component of each cell. Arranged in a double helix.

Dutch metal

An alloy of brass and copper, often used instead of gold leaf in electroscopes.