Archives For Multimeters

Voltage Testers

eiodotcom —  October 8, 2012 — Leave a comment

Today’s EIO post is on Voltage Testers:

Making electrical repairs in your home can save you hundreds of dollars in service costs. One tool you’ll need to get started is a voltage tester. If you have a voltage tester, you can test outlets and light switches to see if voltage is present in their circuits. The most basic type of voltage tester consists of a small, pen-like device with a red lead and black lead extending from it.

What is a Voltage Meter?

    • A voltage meter is a device that is used to measure the strength of an electrical current flowing within an electrical circuit. Essentially what it does is measure the electrical potential (the strength of an electrical charge) at two specific points within the circuit. It then compares these potentials and presents the difference between the two. This difference is the rate at which current florws through the circuit. Voltage meters can be analog devices which use an arrow to indicate the electrical potential, while digital ones provide a read-out.


    • At the center of the voltage meter is a magnet connected at both ends to pieces of magnetized iron. Sitting between the ends of the magnet is a cylinder made of iron. Because of its placement, the cylinder sits within both the positive and negative fields put out by the magnet. A coil of copper wire is wrapped around the far end of the cylinder, all of which is fitted into a housing. At the far end of the wire is a needle, steadied on either side by a spring. Behind the needle is the dial representing voltage. Fitted on the outside of the housing are two more wires, each of which connects to either end of the magnet.

    How Does a Voltage Meter Work?

    • When the voltage meter is at rest, the needle points to the left side of the meter, representing zero electrical potential. The wire leads are attached to two parts of a live circuit. This causes the electricity to polarize the magnet within the meter even further. Should the difference of the potential between the two wires be a positive number, which it would be if any electricity were flowing through the circuit at all, the magnetic field within the meter becomes positively imbalanced, causing the needle to pull from the left side of the meter to the right, indicating how strong the electrical potential is.



Suppliers: VELLEMAN
Type: Digital
LCD Backlight
Features* DMM with automatic polarity function and 3 ½ digit LCD display
* measurements: DC current up to 10A, AC and DC voltage up to 600V, resistance up to 2Mohm
* diode, transistor and continuity test with buzzer
* data-hold function and backlight
* with protection holster


* DC voltage: 200m/2/20/200/1000V
o basic accuracy: –
o input impedance: –
o maximum input: 600V
* AC voltage: 200/600
o basic accuracy: –
o input impedance: –
o frequency range: –
o maximum input: 600V
* DC current: 200µ/2m/20m/200m/10A
o basic accuracy: –
o overload protection: 10A
* AC current: –
o basic accuracy: –
o overload protection: –
* resistance: 200/2k/20k/200k/2M
o basic accuracy: –
o overload protection: –
* capacitance: –
o accuracy: –
* inductance: –
o accuracy: –
* frequency: –
o basic accuracy: –
o overload protection: –
* temperature: –
o basic accuracy: –
* overrange: yes “1”
* continuity buzzer: yes
* transistor test: yes
* diode test: yes
* low-battery indication: –
* maximum display: 1999
* LCD display size: 1.8″ x 0.7″
* ranging mode: manual
* data hold: yes
* backlight: yes
* dimensions: 2.7″ x 5.4″ x 1.2″
* weight (with battery): 13.2275 oz
* power supply: 1 9V 6LR61 battery (incl.)
* packing: –
* accessories: –
* auto power-off: no


Power Supply 9V battery (included)
  • for lamps with one of the following fittings: G13, B15d/G5, G4/GU5.3/GY6.35, E27, E14, E10
  • “beep”-signal confirms that lamp functions normally


Normal LED test range between 2-30mA
All others test range between 20 and 150mA
Power Supply 9V battery (6F22SC, included)
Dimensions 0.26″ x 0.18″ x 0.06″
Weight 2.82oz
  • handy, versatile and portable LED tester
  • types of LED:
    • normal LED
    • bi-colour LED (CA and CC)
    • superflux (spider) LED


  • voltage tester (AC or DC) between 12V and 220V
  • grounding test and testing of broken lines
  • with LCD
  • size: 0.44ft

Multimeters 101

eiodotcom —  May 19, 2012 — 2 Comments

In most electronics projects, there are a few near essential items you need. One such product is the multimeter. Today’s Eio topic is the multimeter.

Analog Multimeter

What is it?

Multimeters are used to measure multiple properties of electronics, most commonly voltage and currents. In its most common usage, people use multimeters to diagnose and narrow down the causes of electrical malfunctions in products such as batteries, power switches, motors, and other electronic components.

There are two main types of multimeters.

  1. Analog multimeter (AMM) – these display its values by using a moving needle across a printed scale.
  2. Digital multimeter (DMM) – these display their values using a digital display that shows the numbers for measurements being taken.

Types of Measurements

Digital Multimeter

As mentioned before, multimeters measure multiple electronic characteristics, hence the name “multiple-meter.” Three major types of measurements are as follows:

  1. The multimeter first acts as a voltmeter and measures amounts of AC/DC volts flowing in a circuit.
  2. As an ohmeter, the multimeter finds the resistance in a current.
  3. As an ammeter, the multimeter measures current flowing through a closed circuit by interrupting that circuit.

Familiarize Yourself with its Parts

Angel Acevado at lays out the different parts of a multimeter that you should become familiar with before use. They are:

  • The dial
  • Pointer or needle
  • Arc shaped lines or scales on the meter dial face
  • A selector switch or knob
  • Jacks or openings in the case to insert test leads
  • Test leads
  • Battery and fuse compartment
  • Zero Adjustment

Finally, all multimeters come with a specific sensitivity range, so make sure you buy one with the amount of frequency you wish to measure. Remember: while higher ranges may allow you to measure higher frequencies, they have less precision and accuracy.

Check out some popular multimeters on our Eio site:


See also: