Digital Multi Meters

Source: fluke.com

Following up on the post discussing VOMs. Here's a link to that post.

https://steemit.com/science/@outwalking/test-equipment-vom

I would like to acknowledge a comment left by @jschindler, he shared a picture of the DMM he uses.

A DMM has been around since about the 1970s, they are similar to the VOM in what measurements the can read but they are more accurate (in DMM terms, this is called resolution). The typical read out is at least down to the thousandths. This accuracy can't be matched by an analog meter because the readout on an analog is the scale and there is limitations on how close they can make the gradients. They are superior to analogs when using them in the field because they can withstand more abuse. The analog's weak link is the meter movement and a DMM has no meter movement.

Due to the DMM being designed with the newer technology, they provide superior input impedance and they have many adapters which allow you to measure additional parameters like temperatures. They have widen the versatility of the unit. There are features like maximum hold where the meter can monitor the voltage and hold the highest value. DMMs usually have a diode tester and a buzzer that tests for continuity. The diode tester be done on some analogs but analogs do not have an audible alarm for a continuity test.

Polarity is shown on a DMM by a '+ or -' symbol. This is helpful if you accidentally connect the test probes incorrectly. It provides an auto range feature so you don't have to change the range switch to get a reading. There is a symbol that will illuminate on the screen that lets you know if you are reading 'kilos' or 'megas'.

Whether you use an analog or a digital meter, this is the most versatile piece of test equipment you will own. As you gain experience in circuitry, you will further appreciate the information provided by this piece of test gear. It will greatly enhance your troubleshooting skills and it is likely the most inexpensive piece of test equipment.