Aneroid Barometer Demonstration Type, with Rubber Bellows

Description

The Aneroid Barometer Demonstration Type, with Rubber Bellows, also known as a demonstration aneroid barometer, atmospheric pressure meter or mechanical barometer, is designed for measuring air pressure and demonstrating the operating principles of an aneroid barometer in educational laboratories. This demonstration instrument features a 100 mm diameter dial enclosed in a transparent acrylic casing, allowing students to observe the internal mechanical movement. Unlike traditional mercury barometers, an aneroid barometer measures atmospheric pressure using a mechanical pressure-sensitive capsule rather than a column of liquid mercury. Changes in external air pressure cause the capsule to deform slightly.

This movement is transferred through a mechanical linkage to the indicating pointer, producing a visible change in the pressure reading displayed on the dial. The transparent acrylic housing is an important educational feature because it allows students to examine how mechanical components respond to pressure changes without dismantling the instrument. The barometer features two pressure measurement scales, graduated from 28 to 31 inches of mercury (inHg) and 960 to 1060 millibars (mbar). These scales introduce students to different pressure measurement units and allow teachers to explain their relationship. One millibar is equivalent to one hectopascal (hPa), a unit commonly used in meteorology.

A distinguishing feature of this instrument is the supplied rubber bellows, which allows users to create controlled pressure changes during classroom demonstrations. When the bellows is gently squeezed, the pressure surrounding the mechanical sensing system increases, causing the barometer mechanism to respond and the pointer to move. This enables teachers to demonstrate the relationship between air pressure and mechanical displacement without relying on naturally occurring atmospheric pressure changes. Students can observe how the pointer responds when pressure is applied and released, helping them understand the operating principle of mechanical atmospheric pressure instruments.

The apparatus is also useful for introducing the concepts of high and low atmospheric pressure and their significance in weather observations. Atmospheric pressure generally changes with altitude and weather conditions. Students can use the barometer to discuss these relationships and compare analogue readings with other suitable pressure instruments. The 100 mm dial provides a practical viewing area for laboratory demonstrations, while the transparent construction supports visual explanations of the pressure-sensitive mechanism. Because the barometer operates mechanically, it does not require batteries, external electrical connections or a laboratory power supply.

The instrument is intended primarily for educational demonstrations and general pressure observations. Its measurement accuracy, calibration tolerance and resolution have not been specified, so it should not be treated as a certified reference instrument. Safety Precautions: Use under appropriate supervision in laboratory or educational settings. Apply pressure gently using the rubber bellows. Avoid excessive compression, impacts and contact with chemicals that may damage the acrylic casing. Do not dismantle the internal mechanism. Each unit is supplied with one 100 mm aneroid demonstration barometer and one rubber bellows. Additional laboratory accessories are not specified as included.

LabChoice Australia supplies aneroid barometers, pressure measurement equipment and physics demonstration apparatus for secondary schools, universities and educational laboratories across Australia.