microbarograph

microbarograph

[¦mī·krō′bar·ə‚graf]

(meteorology)

A type of aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

Microbarograph

 

an instrument for high-precision automatic recording of variations in atmospheric pressure.

The sensing element of a microbarograph is a bellows (aneroid) unit, which is mounted in a miniature pressure chamber that has good thermal insulation. The interior volume of the pressure chamber can be in communication with the atmosphere only if a valve is open, but the inner space of the aneroid capsule is in continuous communication with the atmosphere through a tube. If the valve is closed, a change in the atmospheric pressure relative to the original value in the pressure chamber causes a deformation of the aneroid capsule, which is transmitted to a rod and then, by means of a system of levers, to a pointer. The recorder scale of a microbarograph is 10–30 times larger than for an ordinary barograph. The period of rotation of the drum and its chart may be 10 min to 4—6 hr.

WORKS

Kedrolivanskii, V. G., and M. S. Sternzat. Meteorologicheskie pribory. Leningrad, 1953.

S. I. NEPOMNIASHCHII

microbarograph

A sensitive barograph that records very small transient changes in atmospheric pressure. A microbarograph permits reading directly to 1/10 of a millibar.