Imperialism in the U.S. Essay ... DBQ 15 Imperialism is the policy of extending the role of authority of a nation over a foreign country, usually in material gain, Military expansion and Economical reasons. In the late 1800âs and early 1900âs, the United States went through an era of imperialism.
Portable gas detector. A gas detector is a device that detects the presence of gases in an area, often as part of a safety system. This type of equipment is used to detect a gas leak or other emissions and can interface with a control system so a process can be automatically shut down.
A metal detector is an electronic instrument which detects the presence of metal nearby. Metal detectors are useful for finding metal inclusions hidden within objects, or metal objects buried underground. They often consist of a handheld unit with a sensor probe which can be swept over the ground or other objects.