Induction hob

Induction hob

Induction cookers operate on the following basic physical principle: electric currents are induced in electrically conducting objects, a saucepan for example, by a changing magnetic field. This current heats the saucepan directly. The alternating magnetic field in the cookers is created by an alternating current with a frequency of approximately 20 to 100 kilohertz, which passes through a coil. Saucepans for such cookers are produced from materials that can be magnetised (ferromagnetic materials) in order to improve heat generation.

As soon as the saucepan is taken off the hob, the energy supply to the coil is automatically switched off and the magnetic field is no longer existent. As long as the saucepan is on the hob, the magnetic field is absorbed by the saucepan. If a saucepan of a fitting size recommended by the manufacturers is placed in the centre of the hob, only low magnetic stray fields can be observed in the vicinity of the cooker.

Higher magnetic fields may occur in case of inappropriate use

If inappropriate saucepans or frying pans are used

• no ferromagnetic material,
• with an uneven bottom,
• too small for the hob,

however, higher magnetic fields may occur in the near vicinity of the cooker. The same is true if an appropriate saucepan is not placed in the very centre of the hob, so that the hob is on the verge of being switched off.

At distances to the hobs that are common practice the magnetic flux density falls below the reference value of 27 µT recommended for the relevant frequency range by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) even under unfavourable conditions (inappropriate saucepan not in the centre of the hob).

Recommendations

In order to keep the exposure to these intermediate frequency magnetic fields (at the upper range of the low frequency region) as low as possible,

• only recommended saucepans of a size fitting to the respective hob should be used,
• the saucepans should be placed right in the centre of the hob and
• a minimum distance of 5 to 10 cm to the front edge of the cooker should be kept.

Advice for people with pacemakers

People with pacemakers should be careful since even these low stray fields might have an influence on the function of the pacemaker. If you have a pacemaker, please ask your physician for information on potential interferences.