A digital multimeter works as a sort of electronic tape measure in order to make electrical measurements. It mainly measures amperes, ohms and volts, though some types may come with other special features. There are a number of best practices that should be followed in order to use multimeters correctly and safely.
You can find a great range of multimeters at RS Components.
Selection
Looking at not just basic specifications but also functions, features and overall value of design and production quality is necessary in order to ensure you choose the right digital multimeter for the particular job.
Reliability is of even greater importance in the current age and dependable digital multimeters will have been subjected to a rigorous program of evaluation and testing.
Another of the biggest concerns in the use of a digital multimeter is safety. A multimeter that offers sufficient component spacing, input protection and double insulation can help to prevent damage to the meter and personal injury if incorrectly used. A digital multimeter of good quality needs to be designed to meet the latest and most rigorous standards of safety.
Safety
Safely making measurements begins by selecting the right multimeter for the application and the environment it is in. Instrument user manuals should be read carefully prior to use, with particular attention paid to the Caution and Warning sections.
Safety standards have been established for working on electrical systems by the International Electrotechnical Commission. Meters should meet the IEC category and approved environment voltage rating.
Accurate results
The biggest allowable mistake that can take place under particular operating conditions relates to accuracy. Accuracy for a digital multimeter is normally expressed in the form of a reading percentage, with specifications sometimes including a range of digits included as part of the basic accuracy specification.
This is an indication of how many counts the display’s extreme right side digit could vary.
Measuring
The measurement of voltage is one of the simplest tasks that can be performed by a digital multimeter. The troubleshooting of a circuit normally begins with a test for the proper supply voltage and if there is an issue with the voltage, this will need to be corrected before any further investigation can take place.
Sinusoidal or nonsinusoidal waveforms are associated with AC voltages, with the latter normally caused by harmonics like those that some adjustable speed drives generate. A quality digital multimeter will show the root-mean-square value of such voltage waveforms.
The RMS value is the equivalent or effective AC voltage as a DC value. The majority of multimeters respond by providing accurate RMS reading to pure sine wave AC voltage signals, but cannot accurately measure nonsinusoidal signals. Those signals can only be accurately measured by a digital multimeter with a true RMS designation.
Being able to take true RMS measurements is growing in importance in modern electrical work because of the high amount of harmonic-generating nonlinear loads that are present in electrical circuits.
A digital multimeter is an incredibly versatile electrical tool, with a single device able to perform many different measurements when chosen correctly and used safely.
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