Lake Shore Model 642 Electromagnet Power Supply User’s Manual
Magnet System Design
2-7
Figure 2-5. Typical Curves of Field vs. Current for Various Air Gaps and Pole Cap Sizes (Sheet 3 of 3)
2.4.3
Operation Under Field Control
To obtain a linear field ramp, a magnetic sensor such as a Hall probe is placed in the air gap along with the sample being
tested. The sensor is connected to a Gaussmeter. The output of the Gaussmeter is used to correct the programming input
to the power supply. In this way non-linearity can be corrected. Lakeshore manufactures probes and Gaussmeters for this
purpose.