Which device is primarily used to measure electric current in a marine electrical circuit?

The device primarily used to measure electric current in a marine electrical circuit is known as an ammeter, or ampermeter. This instrument is specifically designed to measure the flow of electric current in amperes (A), which is essential for assessing the performance and safety of electrical systems on a vessel. Accurate readings of current can help identify potential overloads, ensure safe operation, and maintain the overall health of the electrical circuit.

In a marine environment, monitoring current is critical because variations can lead to equipment failure, overheating, or even fire hazards. The ammeter typically connects in series with the circuit, allowing it to measure the current flowing through without interrupting the operation of the devices being powered.

Other devices mentioned have distinct functions that do not relate directly to current measurement. A voltmeter measures voltage, an ohmmeter measures resistance, and a wattmeter quantifies power in watts. Each serves its purpose in evaluating different electrical parameters, but it is the ammeter that specifically addresses the measurement of electric current.