The digital multimeter or DMM for short is the most commonly used equipment to test and measure voltage, current, and resistance in an electrical circuit. These devices are simple to use, and they feature a digital display that shows the voltage, current, or resistance in numerical values. However, you need to make sure that the digital multimeter is calibrated properly if you want to get accurate results.
As a general rule of thumb, a digital multimeter should be calibrated or adjusted to a known-zero value prior to use. If you are not sure how to calibrate a digital multimeter, then you have arrived at the right place. Today we will show you the exact steps you need to follow to calibrate the device so that you can get the most accurate readings possible.
How to Pick the Right Multimeter Calibrator
The first thing that you need to do is to get a multimeter calibrator. There are many options, and finding the best one is not as simple as going into the electronics store and picking out the first one that you see on the shelf. You need to consider a handful of factors first. Check them out below:
- The specifications of the calibrator need to be at least four times better than the one featured on the DMM that is being tested;
- The functions that the calibrator offers need to cover all of the DMM‘s functions. For example, most DMMs have at least five functions.
We highly advise checking the digital multimeter’s manual because it usually recommends functions and minimum specifications that are required for a proper calibrator. Moreover, the manual will include other important information such as the test points and pass/fails limits that need to be evaluated.
How to Calibrate a Digital Multimeter (3 Easy Steps)
Follow the steps below to calibrate your digital multimeter:
- Turn the digital multimeter’s dial to the maximum “ohm” setting in order to set the device to the highest resistance range;
- Now, touch the test probes of the device together. If the calibration is right, then the digital display will read “0 ohms”;
- In case the calibration is not right, you need to keep pressing on the calibration knob until the display reads “0 ohms”.
What is Calibration?
One of the most common mistakes when using a digital multimeter is to do a field comparison check of two meters and think that they are calibrated. This is not what calibration means or how it’s done. While the field check might show if there is a problem, it doesn’t show which meter gives the right readings, and you are left with a guessing game.
To avoid confusing results, you need to properly calibrate the device to make sure that you are getting accurate readings. For calibration to be effective, the calibration standard is required to be more accurate than the digital multimeter that is being tested. Think of this as the same when you set the time on your kitchen oven based on your watch.