AA batteries powered pyrometers

AA

— a popular standard size of replaceable cells, known as "finger-type batteries". Similar cells are also available in the form of rechargeable batteries. In pyrometers, such power is less common than PP3 (see the relevant paragraph) — in particular, because several AA batteries are usually required for efficient operation. However, it is also quite a popular option.

Some models with this type of power supply are also capable of operating from a proprietary battery (see "Battery").