A Simple Apparatus for the Direct Measurement of Magnetic Forces and   Magnetic Properties of Materials
  In this paper, we describe a simple apparatus consisting of a scale, capable of a one milligram resolution, and a commonly obtainable magnet to measure magnetic forces. This simple apparatus is capable of measuring magnetic properties of materials in either a research or an instructional laboratory. We illustrate the capability of this apparatus by the measurement of the force of iron samples exerted on the magnet, the force of a paramagnetic sample, that by a current carrying wire, and the force of a high temperature superconductor. 
Jan A. Makkinje, George O. Zimmerman
cond-mat.mtrl-sci physics.ins-det