A digital multimeter (DMM) could be a take a look at tool accustomed live 2 or a lot of electrical values—principally voltage (volts), current (amps) and resistance (ohms). It is a typical diagnostic tool for technicians within the electrical/electronic industries.
Digital multimeters way back replaced needle-based analog meters thanks to their ability to live with larger accuracy, responsibleness and magnified ohmic resistance. Fluke introduced its first digital multimeter in 1977.
Digital multimeters mix the testing capabilities of single-task meters—the meter (for mensuration volts), meter (amps) and meter (ohms). Often they embody a variety of further specialized options or advanced choices. Technicians with specific desires, therefore, will search out a model targeted for explicit tasks.
The face of a digital multimeter typically includes four components:
- Display: Where measurement readouts can be viewed.
- Buttons: for choosing numerous functions; the choices vary by model.
- Dial (or rotary switch): for choosing primary mensuration values (volts, amps, ohms).
- Input jacks: Where test leads are inserted.
Test leads square measure versatile, insulated wires (red for positive, black for negative) that plug into the DMM. They function the conductor from the item being tested to the multimeter. The probe tips about every lead square measure used for testing circuits.
The terms counts and digits are used to describe a digital multimeter's resolution—how fine a measurement a meter can make. By knowing a multimeter's resolution, a technician will confirm if it's potential to examine a little modification during a measured signal.
Example: If a multimeter offers a resolution of one mV on the four V vary, it's potential to examine modification of one mV (1/1000th of a volt) whereas reading 1V.
Digital multimeters are typically grouped by their number of counts (up to 20,000) they display.
Broadly speaking, DMMs fall into one of a handful of categories:
- General purpose (aka Testers)
Each application with a digital multimeter presents potential safety hazards that have got to be thought-about once taking electrical measurements. Before victimization any electrical equipment, individuals must always initial discuss with the user's manual for correct operative procedures, safety precautions, and limits.