# Polar planimeter

By | 07.08.2018

Here you can view a demonstration of a planimeter in use, presented by Chris Staecker, Associate Proffessor of Mathematics at Fairfield University. The movements along BC and DA are the same but opposite, so they cancel each other with no net effect on the reading of the wheel. The pole arm is marked in script:

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The polae, rounded hinge, and presence of a registering dial indicate this is a Type 2 of the poalr versions manufactured by Amsler. A torn red and white sticker on the bottom of the case originally read: A paper chart for adjusting the tracer arm is held in the lid by black plastic edges and brass screws. The connection with Green's theorem can be understood in terms of integration in polar coordinates: An Historical Encyclopediaed. For instructions, see The Planimeter belongs to a family of measuring tools knowns as integrators and is used to determine the area inside an irregular shape.

Case is in good condition - tools appear to have minimal use.

### Polar and Linear Planimeters

It is also marked: Pooar the tracing is complete, the scales at the measuring wheel show the shape's area. The carriage for adjusting the tracer arm holds the metal measuring wheel and vernier. Connected to the arm ME is the measuring wheel with its axis of rotation parallel to ME.

Types 8 and 9 are wheel-and-disc polar planimeters.

## Planimeter

It is made of German silver with a gold-colored coating. Planimeter expert Joachim Fischer dated this object to about A serial number is marked underneath the tracer arm and the weight: Here you can view a demonstration of a planimeter in use, presented by Chris Staecker, Associate Plnimeter of Mathematics at Fairfield University.

The round piece has some crud on the edges. Joachim Fischer to Peggy A. The tracer arm and pole arm are connected by a hinge and form a circle around the white plastic planimwter wheel and vernier when the instrument is closed.

A point extending from polaf carriage holding the measuring wheel allows the user to turn the planimeter vertically and use the other end of the tracer point. Underneath the arm is stamped: A cylindrical weight fits over a peg at the end of the pole arm.

### Polar Planimeter: Engineering | eBay

The plating has worn away from the handle for the tracer point. Proportion, Adjustement [ sic ] on tracer-arm, and Value of unit of the Vernier. At the end of one link is a pointer, used to trace around the boundary of the shape to be measured.

The top of the tracer arm is marked in script: The operator sets the wheel, turns the counter to zero, and then traces the pointer around the perimeter of the shape. The plannimeter shows a Type 3 Amsler polar planimeter and explains how to use the instrument. The instrument resembles the Robertson-Amsler planimeter shown in Hawkins's Indicator Catechism New York, and advertised in as an olanimeter planimeter.

This is a Type 6 polar planimeter from the workshop founded by Panimeter Amsler in Schaffhausen, Switzerland, in The measuring wheel now moves in the opposite direction, subtracting this reading from the former.

A worn instruction card MA. The presence of a registering dial and the screw thread on the post extending from the measuring wheel indicates that this example is a type 2.

The polar planimeter is restricted by design to measuring areas within limits determined by its size and geometry. A Collector's Guide Mendham, N.

Dimensional instruments Technical drawing Mathematical tools Measuring instruments.

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