1. Digital Multimeter Introduction
Choosing the right meter Category
Category ratings are designed to protect users from transient overvoltage conditions (intermittent voltage spikes caused by electrical equipment surges during starting, capacitors, inductive circuits, and lightning strikes)
It is these unintended and intermittent transient voltage spikes that can be dangerous to users with too low of meter category rating

2. Digital Multimeter Introduction
Choosing the right meter Category
With the likely hood of working in multiple different category environments always choose a meter that will be safe for working on the HIGHEST category that could potentially be accessed
Choose a Steady State Voltage rating that meets the maximum voltage you will encounter
ALWAYS choose the Category FIRST and then a steady state voltage value
A CAT III–600V meter will provide far superior transient voltage protection than CAT II–1000V meter

3. Digital Multimeter Introduction
Choosing the right meter Category
TEST LEADS: Be sure your test leads have an equal, or HIGHER, Category and Voltage rating than the chosen meter
Meter system only as-good-as its components (as strong as the weakest link)
Quality Leads should be rated CATIII 1,000V and CAT IV 600 and UL Listed
Double insulated

4. Digital Multimeter Introduction
TEST LEADS:
Protective tips and accessory clips make connecting to circuits and components easier and safer, but change the category rating of the test leads.
With Protective tips: 1000V CAT III & 600V CAT IV
WithOUT Protective tips: 1000V CAT II & 600V CAT III (LOWER Rating)

5. Review for Understanding
What are the two types of signals commonly converted and displayed on a DMM?
True of False: DMMs can measure a wide range of signals with accuracy.
How many ohms is 92.2 kΩ
Explain the 4 basic operations DMMs help us to perform.
Define High Impedance. Why is it important when testing electronic circuits?
Answers
Rapid electrical pulse signals & Steady state or Slow Changing signals
True
92,200
Convert Electrical Signals into Understandable Values
Perform highly accurate electrical measurements
Solve electrical equation calculations
Enable testing of sensitive electronic circuits
High impedance is high resistance and limits the amperage draw from an electronic circuit to protect it.