Lake Shore Cryotronics, Inc. DSP Gaussmeter Model 475

Lake Shore combined the technical advantages of digital signal processing with over a decade of experience in precision magnetic field measurements to produce the first commercial digital signal processor (DSP) based Hall effect gaussmeter, the Model 475. DSP technology creates a solid foundation for accurate, stable, and repeatable field measurement while simultaneously enabling the gaussmeter to offer an unequaled set of useful measurement features. The Model 475 is intended for the most demanding DC and AC applications. In many cases, it provides the functionality of two or more instruments in a field measurement system. The power of DSP technology is demonstrated in the superior performance of the Model 475 in DC, RMS, and Peak measurement modes. Advanced features The Model 475 combines hardware and firmware elements to create advanced features that facilitate automation and materials analysis. Field control A built-in PI control algorithm turns the Model 475 into an essential building block for magnetic field control in electromagnet systems. It, along with a voltage-programmable magnet power supply, is all that is needed to control stable magnetic fields in an electromagnet at the user-specified setpoint. One of the built-in analog voltage outputs drives the program input of the power supply for either bipolar or unipolar operation. High-speed data transfer The IEEE-488 interface can be set to send readings in binary format rather than the more common ASCII format. This reduces interface overhead, enabling real-time reading rates up to 100 new readings per second. Temperature compensation is not available at the highest interface rate. Data buffer Internal memory provides storage for 1,024 field readings in a data buffer. The buffer can be filled at high speed, up to 1,000 readings per second, which is as much as ten times faster than the computer interface. Stored readings can then be retrieved over interface at slower speed and processed offline. A trigger input can be used to initiate the data log sequence. Slower sample rates can be programmed if desired. Trigger in and trigger out A TTL-level hardware trigger into the instrument can be used to initiate the data log sequence. A TTL-level hardware trigger out indicates when the instrument completes a reading, and can be used to synchronize other instruments in the system. An IEEE-488 software-based trigger can be used like the hardware trigger in. Model 475 Features Full-scale ranges from 35 mG to 350 kG DC measurement resolution to 0.02 mG Basic DC accuracy of ±0.05% DC to 50 kHz frequency range (probe-dependent) 15 band-pass and 3 low-pass AC filters Peak capture to 20 µs pulse widths Data buffer sampling rates to 1000 readings per s Computer interface sampling rates to 100 new readings per s Integrated electromagnet field control algorithm Standard probe included Specialized and custom probes available CE mark certification