What is a digital voltmeter used for in automotive diagnostics?

A digital voltmeter is specifically designed to measure voltage levels in a circuit, making it an essential tool for automotive diagnostics. It allows technicians to accurately assess the electrical system's performance, identify potential issues, and ensure that components are receiving the correct voltage. This is critical when troubleshooting problems related to battery health, alternator output, and circuit functionality.

For example, if a vehicle is experiencing starting issues, a digital voltmeter can be used to check the battery voltage and verify that the ignition system is getting adequate power. The precise measurements provided by a digital voltmeter are crucial for a successful diagnosis and repair in electrical systems.

The other options provided are unrelated to the primary function of a digital voltmeter. Fuel pressure is typically measured using a fuel pressure gauge, air quality is assessed with air quality sensors or monitors, and tire pressure is checked using a tire pressure gauge. Therefore, the role of a digital voltmeter is distinctly focused on voltage measurement, which is why it is the correct answer.