An electric tester, also known as a test meter or electrical tester, is a handheld device used to measure various electrical parameters in electrical circuits and equipment. Electric testers come in different types and are designed for specific purposes, including testing voltage, current, resistance, continuity, and sometimes other parameters like capacitance and frequency.

The primary uses of electrical testers include:

1. Voltage Testing: Electric testers can measure the voltage present in electrical circuits and outlets. This is essential for verifying the presence of voltage, identifying live wires, and determining if electrical devices are receiving the correct voltage.

2. Continuity Testing: Continuity testing is used to check if there is a continuous electrical path between two points in a circuit. Electric testers can emit an audible beep or display a visual indication when continuity is detected, helping to identify open circuits, broken wires, or faulty connections.

3. Resistance Testing: Resistance testing is used to measure the resistance of electrical components or conductors. Electric testers can assess the resistance of wires, resistors, and other components to ensure they are within the expected range and functioning correctly.

4. Current Testing: Some electric testers are capable of measuring electrical current flowing through a circuit. This is useful for troubleshooting and verifying the current draw of electrical devices or components.

5. Safety Testing: Electric testers are also used for safety purposes, such as testing for the presence of voltage before working on electrical systems, ensuring proper grounding and insulation, and identifying potential electrical hazards.

Electric testers are essential tools for electricians, technicians, and homeowners working on electrical systems and appliances. They help ensure the safety, reliability, and proper functioning of electrical equipment by allowing users to perform various diagnostic tests and measurements accurately. It's crucial to use the appropriate type of electric tester for the specific task at hand and to follow proper safety procedures when working with electricity.