It also alternates the internal temperature of the panel on the same display. The instrument has an 18-character red LED alphanumeric display, which can be programmed with any standard PC Keyboard to read alphabets (A-Z), numerals (0-9) and some special characters such as *, +, -, etc. Simultaneously, a built-in temperature sensor monitors the temperature of the exhaust air within the panel and indicates it at regular intervals. The Display has a non-volatile memory - hence, on power failure, the last programmed message remains in memory and will be displayed on power resumption.