US Patent 11990022 Self-testing duct environment detector

Devices, methods, and systems of a self-testing duct environment detector are described herein. One self-testing duct environment detector system includes a first portion to be mounted outside of a duct, the first portion having a detector housing with a space therein, the space having a detector with a sensing chamber and a self-testing sensing apparatus therein, wherein the self-testing sensing apparatus determines whether airflow through the detector housing is above a threshold and a second portion and third portion each configured to extend into the duct, wherein the second portion has at least one inlet aperture formed therein and wherein the third portion has at least on outlet aperture therein.