Energy It is equal to the energy expended (or work done) in applying a force of one newton through a distance of one metre. However energy is also expressed in many other units not part of the SI, such as ergs, calories, British Thermal Units, kilowatt-hours and kilocalories, which require a conversion factor when expressed in SI units. The SI unit of energy rate (energy per unit time) is the watt, which is a joule per second. Thus, one joule is one watt-second, and 3600 joules equal one watt-hour. The CGS energy unit is the erg and the imperial and US
Scientific echosounder Scientific echosounder A scientific echosounder is a device which uses sonar technology for the measurement of underwater physical and biological components—this device is also known as "scientific sonar". Applications include bathymetry, substrate classification, studies of aquatic vegetation, fish, and plankton, and differentation of water masses. Scientific echosounder equipment is built to exacting standards and tested to be stable and reliable in the transmission and receiving of sound energy under the water. Recent advances have led to the development of the digital scientific echosounder, further enhancing the reliability and precision with which these systems operate. Modern scientific echosounders are reliable, portable,