page_title: Balanced-arm lamp
section_title: Lamps balanced with springs
hierarchical_section_title: Balanced-arm lamp / Lamps balanced with springs
caption_attribution_description: English: Pressure and expansion springs
context_page_description: A balanced-arm lamp, sometimes called a floating arm lamp, is a lamp with an adjustable folding arm which is constructed so that the force due to gravity is always counteracted by springs, regardless of the position of the arms of the lamp. Many lamp brands as well as other devices, such as drawing boards, use this principle.
context_section_description: There are many variations of construction with springs. Springs can be located on the mechanical equivalent of the forearm or the upper arm, or both, as well as nearer the base. Some lamps use tension springs, and others use compression springs. The adjacent image shows (left to right) a compression spring at rest, then under load, followed by a tension spring at rest, and then under load. 
  Springs have a limited lifting capacity and extension length.
  Some springs can resonate, producing low-level unwanted noise.
caption: Compression and tension springs at rest and under load
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