An auxanometer (Gr. Шаблон:Lang= "to grow" + metron= "measure") is an apparatus for measuring increase of growth in plants.[1]
In case of an arc-auxanometer (see picture), there is a thin cord fixed to the plant apex on one end and a dead-weight on the other with a pointer indicating against an arc scale. In some forms it passes over a pulley which has a pointer attached to it. When the plant's height increases, the pulley rotates and the pointer moves on a circular scale to directly give the magnitude of growth.[2] The "rate of growth" is a derived measurement obtained by dividing the length of growth measured by the auxanometer, by the time said measurement took. It is also called an arc-indicator. These simple types of auxanometer have been replaced by rotation sensors at the fulcrum point linked to dataloggers with a balancing beam attached to the growing tip/plant apex.
Sensitive auxanometers allow measurement of growth as small as a micrometer,[3] which allows measurement of growth in response to short-term changes in atmospheric composition.[4] Auxanometers are used in laboratory,[4] the field,[5] and the classroom.[6]
