HHS 5204-36 Circular Helmholtz CoilsThe Helmholtz-Coils are especially designed to generate precisely defined magnetic fields from DC to the upper end of the audio frequency range and beyond. The generated fields are in strong linear relation to the coil current. The field strength can be calculated exactly by analytical (or numerical) methods, based on the coils' geometry, the number of turns, and the coil current. Therefore the HHS 5204-36 is ideally suited for the calibration of magnetic field probes or sensors. Due to the high-temperature proof Teflon wire packet, it is possible to generate magnetic fields up to approx. 3000 A/m for short times. Typical applications are magnetic immunity testing according to automotive standards or MIL-STD 461. When generating magnetic fields with Helmholtz coils the coil current is directly proportional to the magnetic field strength. The calibration of the magnetic field is finally traceable to a current measurement (or to a voltage drop at a known resistor). The Helmholtz Coil itself does not require calibration. Alternatively, a small loop sensor can be used to determine the actual field strength.
The Helmholtz-Coils should be installed on a desk in a sufficiently large separation from sources of unintentional magnetic fields, e.g. transformers in power supplies, conductors carrying high currents, computer monitors, loudspeakers, cathode ray tubes (CRT), and more.... All kinds of magnetic material (e.g. steel, Nickel, Cobalt) should be removed from the near surrounding of the coil. The wires which are used to connect the current source with the Helmholtz- Coil should be twisted to avoid an unwanted injection of magnetic flux. The coil terminals are assigned with the characters A, B, C, and D. The generator (current source, audio-amplifier...) is connected to the terminals A and C, the terminals B and D are connected with the short cable supplied with the coil. Specifications:
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