Ammeters are used to measure the electrical current of a circuit. The current is measured in amperes and this is how the device was named. Many people call them "ampmeters" but this is a common mistake. These meters are generally used to measure both AC and DC current in the range of +/- 60 amps.

There are a few types of meters to choose from. There are traditional analog ammeters, newer digital ones as well as clamp meters. Consider each type of equipment before you buy ammeters for your business. Each individual meter has the capacity to measure different ranges, so think about that as well.

1. Train your workers to read analog ammeters. It's not hard, once they get used to it, but the meters must be read correctly for the test to be accurate.

2. Use digital ammeters to reduce user error. These display the reading in digits, leaving no room for interpretation.

3. Increase productivity by using clamp ammeters. These meters eliminate the need for disassembling the circuit to be measured.

Action Steps
The best contacts and resources to help you get it done

Go with traditional analog ammeters

These meters have been around for years and years. They are inexpensive and small. The only downside is that the reading must be taken properly; a needle swings quickly and rests at the amperage value of the circuit you're measuring, then you carefully look to see the value at which the needle rests.

I recommend: Buy reliable yet low-cost ammeters in bulk at Allied Electronics. The analog ammeter from Real Goods Solar ranges from zero to 30 amps.

Let your workers use digital ammeters to make their jobs easier

A digital ammeter displays its readings using digits. This makes for easy reading with no interpretation needed: Simply glance at the display and move on. These meters do tend to be a bit more expensive.

I recommend: Request a quote for the non-contact ammeter at DirectIndustry. Take a look at the selection of digital ammeters for sale at Trumeter.

Simplify your job by using clamp ammeters

Clamp meters are made so electricians don't have to disconnect any wiring when they want to take a reading. These tools have clamps that encircle the wires in question and perform the necessary tests. These devices are also known as 'tongs' or 'amprobes.'

I recommend: Measure both amps and voltage at the same time with the clamp meter from LicensedElectrician.com. Check out the Fluke milliamp process clamp meter from Valuetronics.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  If you need to use pricey test equipment with all the bells and whistles, try finding a used ammeter for sale. Refurbished equipment must be brought to factory standards before it is sold; you can also find used ammeters being sold by electricians who are no longer in the business.
• •  High-current ammeters with shunt resistors should have a low resistance value so they don't interfere with the circuit's current. Be careful when using these meters so you don't blow a fuse or cause injury to yourself or someone around you.