Astrophysics (index)

Bolometer

(instrument measuring heat produced by radiation)

A Bolometer is an instrument for measuring Electromagnetic Radiation by allowing the radiation to heat a Metal whose electrical resistance is dependent upon its Temperature. As the material heats, the change in resistance is noted.

Bolometers measure a relatively wide range of Frequencies, thus are more suited to measuring energy over a wide range or estimating the total incident energy from a source.

Bolometers are not necessarily the most sensitive instruments at some frequencies. They can be made competitive in the submillimeter to 1 mm range (Far Infrared). To achieve sensitivity, such bolometers are run near absolute zero.

Micro-bolometers are used for imaging, with on the order of 100 x 100 pixels, and more recently approaching 1000 x 1000.

Note that the adjective Bolometric which has the obvious meaning "having to do with bolometers" is very often used to imply the sum of all EMR, e.g., from a source. This is the use in terms like Bolometric Correction, Bolometric Luminosity, and Bolometric Magnitude. This came about because Bolometers do indeed measure the power of the EMR striking it across a wide band, wider than many other instruments, though they are not actually perfect in that regard, and an Earth-bound bolometer will necessarily miss radiation not in Atmospheric Windows.


(instrument type,EMR,submillimeter)
http://en.wikipedia.org/wiki/Bolometer

Referenced by:
Atacama Cosmology Telescope (ACT)
Atacama Pathfinder Experiment (APEX)
Atacama Submillimeter Telescope Experiment (ASTE)
AzTEC-3
Bolometric Luminosity
Focal Plane Array (FPA)
Green Bank Telescope (GBT)
GISMO
James Clerk Maxwell Telescope (JCMT)
MUSTANG
SCUBA
South Pole Telescope (SPT)
Transition Edge Sensor (TES)

index