Wiegand is the trade name for a technology used in card readers and sensors, particularly for access control applications. Wiegand devices were originally developed by HID Corporation.
A Wiegand card looks like a credit card. It works according to a principle similar to that used in magnetic-stripe cards, such as those used with bank automatic teller machines (ATMs). Instead of a band of ferromagnetic material, the Wiegand card contains a set of embedded wires. The wires are made of a special alloy with magnetic properties that are difficult to duplicate. This makes Wiegand cards virtually counterfeit-proof. The set of wires can contain data such as credit card numbers, bank account numbers, employee identification information, criminal records, and medical history. The card is read by passing it through, or bringing it near, a device called a Wiegand sensor.
Wiegand effect occurs over a wide range of temperatures. Therefore, access control devices using this technology can function in hostile environments. Other assets include rapid response time and portability. These properties make Wiegand cards and readers ideal for use in the field.