An Introduction to Card Testing

Ultimately, the magnetic stripe on a card exists for one reason: to store data for later use. If the data can not be retrieved when your customer swipes the card, you negatively impact customer satisfaction. Testing your magnetic stripe before the cards you ship meets the expectations of your customers.

We measure the quality of magnetic stripe against two ISO standards. ISO/IEC7811-2 provides the specification for low coercivity (loco) tape, and ISO/IEC7811-6 provides the specifications for high coercivity (hico) tape.

The magnetic stripe on a loco card is 300 Oersteds, and the hico cards range between 1250 and 4000 Oersteds. Examples of loco cards include ID, access, and mass transit cards while the financial industry uses hico cards for bank cards.

Types of Tests

Since we have separate ISO reference standards to test loco and hico cards, we can expect different tests for each standard. To test loco cards, we perform window, resolution, and erasure tests.

The window test verifies the amplitude on the stripe falls within acceptable levels. The resolution test ensures that stripe output maintains an acceptable level at higher bit densities. The erase tests intentionally erases the stripe and makes sure the residual amplitude remains low after the erasure.

To test hico cards, we check for demagnetization and distortion. To pass, a magnetic stripe should resist erasure when exposed to a household magnetic, such as a refrigerator magnet. Loco cards because they are encoded with a lower Oersteds value are vulnerable to accidental demagnetization and data loss.

Distortion tests the stripe for parity errors that arise from extra bits. Jitter is another form of distortion that happens when the encoded bits on the stripe appear out of order.

Your Testing Needs

The decision to test your cards to ISO standards should be an easy one to make. Perhaps the biggest decision is whether or not you buy your own equipment or outsource your testing services to a neutral lab.

Q-Card offers solutions to help you ensure total card quality in your lab or in ours. Future installments of the Q-Card Hotline will discuss the benefits of testing in your lab versus outsource. Plus we’ll cover many of the concepts we outlined in this article with more detail.