How to Measure Current with a Clamp Meter
A clamp meter measures electrical current by sensing the magnetic field around a conductor. Its hinged jaws let you take a load-current reading without cutting the wire or placing the meter in seri...
Is Red Wire Positive or Negative
A red wire is not always positive. Its meaning depends on the electrical system, the local wiring standard, and the way the circuit was installed. In low-voltage direct current (DC) systems, red co...
How to Identify Line and Load Wires
Line and load describe the direction of power at a specific electrical device. The line side receives power from the upstream source. The load side sends power to a light, receptacle, or another do...
How to Check Fridge Temperature with Thermometer
The most reliable way to check a refrigerator’s temperature is to leave an appliance thermometer inside the unit. A refrigerator should remain at 40°F (4°C) or below, while a freezer should stay ...
How to Test Spark Plug With Multimeter
A digital multimeter can help you check a removed spark plug for an internal open circuit, abnormal resistance, or a short through the insulator. However, it cannot confirm that the plug will produ...
How to Use A Digital Clamp Meter to Measure Voltage
A digital clamp meter can measure voltage only when the meter supports voltage testing and you use its test leads. The clamp jaws normally measure current around a single conductor. They do not mea...
How to Test a Car Battery with a Multimeter
If your car is slow to start or will not start at all, you can test the car battery at home with a digital multimeter before deciding what to do next. A few simple voltage checks can show whether t...
How to Test Purge Valve with Multimeter
A multimeter can help you check the electrical condition of an automotive EVAP purge valve. The main test measures the resistance of the valve’s internal solenoid coil. This test can identify an op...
How to Check 240 Voltage with a Multimeter
To check a 240V outlet with a multimeter, set a properly rated meter to AC voltage and measure between the two hot slots. In a typical North American residential system, a working 240V circuit shou...