HHS 5218-100-2.5 – Helmholtz Coil
Helmholtz-Coils are especially designed to generate precisely defined magnetic fields from DC to ca. 3 kHz. The generated fields are in a strongly linear relation to the coil current. The fieldstrength can be calculated exactly by analytical (or numerical) methods, based on the coils’ geometry, the number of turns and the coil current. 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 is usually considered as primary standard due to the easily calculable relation between current and field strength. If this relation should be controlled, a loop sensor (only AC) or a Hall probe (DC- and AC- field) can be used to determine the actual field strength. A short set of connecting cables is included in the scope of delivery.
| Number of turns (per Coil): | 100 |
| Maximum coil current: | 40 A, 5 min. |
| Nominal coil current: | 20 A continuous |
| Coil factor for 0.6m distance | 86.05 A/m |
| Maximum magnetic field strength: | ca. 3442 A/m max. 5 min @ 40 A., dist. 0.6 m |
| Distance for best homogeneity: | 1.00 m |
| Magnetic field strength caused by 1 A coil current: | 70,45 A/m (Coil dist. 1.00 m) |
| Nominal magnetic field strength: | 1409 A/m continuous @ 20 A, dist 1.00 m |
| Current required for 100 A/m at best possible homogeneity: | 1.42 A (Coil dist. 1.00 m) |
| Outer mechanical dimensions: | 2.00 m x 1.91 m x 1.27 m |
| Average electrical side length: | 1.844 m |
| Maximum coil separation: | 1.20 m |
| Usable frequency range: | 0 – 3 kHz |
| Inductance (per coil): | 60.5 mH |
| Inductance (Pair of coils, coil dist. 0.9 m*): | 133 mH |
| Resistance (per coil): | 2.5 Ohm |
| Resonant frequency (Pair of coils): | > 8 kHz |
| Weight: | 91 kg |