The Acclimate 2251TMB photoelectric detector uses advanced onboard software to combine signals from photo and thermal elements to create a true multicriteria detector capable of rejecting nuisance sources while still responding quickly to fires. It includes thermal detection at 135°F. The Acclimate detector can adjust its sensitivity according to its environment. It continuously samples the air in the environment and adjusts its detection parameters and alarm threshold accordingly. It does this automatically without user intervention. There is no need for an installer to set sensitivity levels at the control panel. —System Sensor