What is an amp meter and how/when do I use one?

The short answer – it’s a device you use when you would like to measure the electrical current through a circuit.

As a quick side note, an amp meter (or ammeter) is to a multimeter as the corkscrew is to a jackknife. A multimeter includes the amp meter’s functionality and can measure other things as well (resistance, voltage, etc etc).

An amp meter measures – you guessed it – AMPS. An “amp”, or ampere, is a unit of measurement used to describe the speed at which electrons flow through a circuit (somewhat like mph). An amp meter measures the magnetic field of the conducting wire you clamp it around, and from there (ask if you need a better explanation of the magic) it gives you the amp reading. Below this post are the step-by-step instructions for hooking up and reading an amp meter…

(* jeopardy theme song *)

So, you now have a number.  If you think of the amperage as a speed and someone standing next to you suddenly said “50 mph,” you would have no context to associate that with (You might even step just a little farther away from that person). Same with the amperage measurement,  you need to find out what reading you’re aiming for. I can give you some examples, but then you are on your own as this varies situation by situation.

– When measuring an ignitor, you want to find the amperage “speed limit” on the back plate (it should say something like 2.5-3.0A)

– When measuring a burner switch, you can look the amperage up online based on your model or on the back of the switch (for example, 15A)

May all your readings be in a reasonable range,




  1. Decide if you are measuring AC or DC and flip the switch to the proper setting on your device. (DC goes one direction and is usually found in baKlein amp metertteries, AC alternates directions and is often used for household appliances.)
  2. Which wire are you taking the reading from? Either supply wire (the wires supplying power to the device).
  3. Make sure the item you want to take a reading from is on – BE WARY OF ELECTROCUTION … the wires are “hot”.
  4. Clamp the meter around your chosen wire and read the amps from your screen. Done.
This entry was posted in Electrical and tagged , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s