Auxanometer

An auxanometer (Gr. auxain= "to grow" + metron= "measure") is an apparatus for measuring increase of growth in <a href="/facts/Plant/X5BMDMvS">plants</a>.
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 <a href="/facts/Pulley/Mrq15sdg">pulley</a> 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 <a href="/facts/Magnitude_(mathematics)/KCn9PoF0">magnitude</a> of growth. 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 These simple types of auxanometer have been replaced by rotation sensors at the fulcrum point linked to dataloggers with a balancing beam attached to the growing tip/plant apex.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 <a href="/facts/Micrometre/7eDFxD2L">micrometer</a>, which allows measurement of growth in response to short-term changes in <a href="/facts/Atmospheric_chemistry/EbmISm33">atmospheric composition</a>. Auxanometers are used in laboratory, the field, and the classroom.

Auxanometer open-in-new

Auxanometer