Find out more about our EM label and hard tag options. The EM label are made at our headquarter in Witzhave. Made in Germany.
We are one of the last producers of EM label world wide. Despite the fact that the demand for other label technologies is rising, we are still continuing our production of EM label. They are available on sheet or roll, with or without dummy barcode.
The electromagnetic EAS system creates a low frequency electromagnetic field (fundamental frequencies between 70 Hz and 1 kHz are typically used) between two pedestals at an exit or checkout aisle. The field continuously varies in strength and polarity, repeating a cycle from positive to negative and back to positive again. With each half cycle, the polarity of the magnetic field between the pedestals changes.
In response to the changing magnetic field created by the transmitter, the magnetic field domain of the tag material abruptly “switches” as the field strength varies past a particular point, whether positive or negative, during each half of the transmit cycle. This abrupt change in the magnetic state of tag material generates a momentary signal that is rich in harmonics (multiples) of the fundamental frequency. Using electronic signal processing techniques, the system identifies that the harmonics are at the right frequencies and levels, and that they occurat the proper time in relation to the transmitter signal. If the criteria are met an alarm occurs.
Detection of the tag is achieved with a transmitter and receiver.
The transmitter and receiver work together to sense harmonics and sum or difference signals generated by the non-linear magnetic response of the material under a mixture of low-frequency (in the 10 Hz to 1000 Hz range) magnetic fields.
When the ferromagnetic material is magnetized, it biases the amorphous metal strip into saturation, where it no longer produces harmonics. Deactivation of these tags is therefore done with magnetization. Activation requires demagnetization.
Due to the convenient dimensions of the tags, and their very low cost, this system is popular in libraries.