An auxanometer is an apparatus for measuring increase or rate of growth in plants. In case of an arc-auxanometer (see picture), there is a wire fixed with the plant apex on one end and a dead-weight on the other. 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. Sensitive auxanometers allow measurement of growth as small as a micrometer,which allows measurement of growth in response to short-term changes in atmospheric composition. Auxanometers are used in the laboratory, the field,and the classroom.
20th Jan 2015