Tailgating
1) More than one individual entering a secure area using one access card.
2) Following an authorized person into a secure area. Also Known As - Piggybacking. See Anti Passback.

Telephone Entry
An access control system that allows users outside a secure area to use a telephone to contact someone inside the secure area and request access.

Timezone
A specified period of time in which access is allowed. A variety of timezones may be defined to accommodate the access needs of a variety of people.

Transients
Electrical surges or spikes conducted through power or data lines. Transients are typically generated as electrical devices are turned on or off.

Transorb
An electrical suppression device. See: Suppression.

Turnstile
An entryway that uses a mechanical device to restrict entry to one person at a time.