These are the modern replacements for the Gouy Balance and are based on the original patented design of Professor Evans from Imperial College London.

Magnetic Susceptibility is defined as:- THE RATIO OF THE INTENSITY OF MAGNETISM INDUCED IN A SUBSTANCE TO THE MAGNETISING FORCE OR INTENSITY OF FIELD TO WHICH IT IS SUBJECTED

The traditional technique, the Gouy method, employs a conventional laboratory laboratory balance and large permanent magnets. The magnets remain stationary while the sample is caused to move, giving apparent gain or loss in sample weight. The MSB - MK1 works on the basis of a stationary sample and moving magnets. Two pairs of magnets are placed at opposite ends of a beam making a balanced system. Introduction of the sample attempts to deflect the beam and the movement is optically detected. A compensating force is applied by a coil between the other pair of magnets. The current required to maintain equilibrium of the balance beam is proportional to the force exerted by the sample.

The MSB - MK1 is recognised in hundreds of teaching and research laboratories throughout the world. Based on the Evans' design, it offers a number of significant advantages over the traditional methods.