As an electrician, you know that ohmmeters measure the electrical resistance of conductors and circuits. These meters are generally used for industrial customers in plants and factories.

There are a few types of meters to choose from. There are traditional analog meters, newer digital ohmmeters as well as clamp meters. The selection narrows further: micro-ohmmeters are used to measure lower ohmage and megohmmeters, also known as high resistance testers, are used to measure very high ohmage. Carefully consider your needs before you buy.

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

2. Give each employee an electronic ohmmeter with a digital display to reduce user error. This type of meter displays the reading in digits, leaving no room for interpretation.

3. Increase productivity by using clamp ohmmeters. 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 a traditional electric ohmmeter with an analog display

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 value of the circuit you're measuring, then you carefully look to see the value at which the needle rests.

I recommend: The analog ohmmeter at Hotek Technologies measures from .05 to one megohm. Try out the hand-cranked megohmmeter from Optimum Energy Products.

Let each worker use a digital ohmmeter to make his job easier

A digital ohmmeter 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: Set up a portable microhmmeter to test your industrial customers' circuits; you can get one from Sefelec. Buy an economical megohmmeter from Cole-Parmer.

Simplify your job by using clamp-style electronic ohmmeters

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.'

I recommend: AEMC Instruments offers a digital clamp meter that measures up to 400 ohms. You can find an analog clamp meter at Tequipment.com. The meters offered at these sites have the capability to measure other things as well as ohms.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Make sure your employees know how to use an ohmmeter before allowing them to use it on a job with your customers; teach them to calibrate it against known electrical sources. Also, determine what safety precautions need to be taken while using one of these meters.