Energy & Current
An energy meter measures both Current and Voltage to calculate Power and Energy. Sometimes it is sufficient to only measure the current, for example to monitor the on/off state of a piece of equipment, or to monitor for faults.
Common applications are:
Runtime monitoring – keep track of equipment usage and performance
Fault detection – monitor for broken light bulbs or unusual load conditions
Slave control – let the on/off state of one machine control other equipment
Diagnostics – estimate power usage on known loads
Electrical current can be measured in two ways; using a shunt or measuring the magnetic field.