Electronic Testing Equipment and Their Types

The testing equipment used to detect faults in the operation of electronic devices by creating stimulus signals and capture responses from electronic devices under test is known as electronic test equipment. If any faults are detected, then identified faults can be traced an rectified using electronic testing equipment. Most often all electrical and electronic circuits are tested and troubleshooted to detect faults or abnormal functioning if any.

Therefore, testing equipment is necessary to find and analyze the circuit conditions, for checking electronic test equipment and maintenance in various industries. Many industries utilize different types of electronic test equipment ranging from the very simple and inexpensive to complex and sophisticated ones.

Types of Electronic Testing Equipments

The Basic Electronics Testing Equipments Under this Category Include the Following

Voltmeter

A basic electronics device or instrument used to measure voltage or electrical potential difference between two points in electrical circuits is known as voltmeter. There are two types of voltmeters: analog and digital.  An analog voltmeter moves a pointer across a scale in proportional to the voltage of the electrical circuit. A digital voltmeter measures an unknown input voltage by converting the voltage to a digital value by using a converter and then displays the voltage in numeric form.

Ohmmeter

An electrical instrument that measures electrical resistance is known as an ohmmeter. The instrument used to measure small value of resistance are micro-ohmmeters. Similarly meg-ohmmeters is used to make large resistance measurements. Resistance values are measured in ohms (Ω). Originally, ohmmeter is designed with a small battery to apply a voltage to a resistance.

It uses a galvanometer to measure the electric current through the resistance. The scale of the galvanometer was marked in ohms (Ω), because the fixed voltage from the battery assures that the resistance decreases and the current through the meter  increases.

Ammeter

A measuring instrument which is used to measure the electric current in a circuit is known as an ammeter. The units of measurement for electric current is amperes (A)  Earlier ammeters were laboratory instruments which depend on the earth’s magnetic field for operation.  In an era of the 19th century, improved instruments were designed which could be placed in any position and allows accurate measurements in electric power systems.

The smaller currents can be measured by using milliammeters or micro ammeters, units of measuring the smaller current are in the milliampere or micro-ampere range. There are different types of ammeters such as moving-coil, moving magnet and moving-iron, etc.

Multimeter

A multimeter is an electronic instrument used to measure the three basic electrical characteristics: voltage, current and resistance. It has multiple functions and acts like ohmmeter, voltmeter and ammeter and also used for household wiring, electric motors, testing batteries and power supplies. The multimeter is a handheld device with a needle over a numeric LCD digital display for indication purpose. It is also used to test continuity between two points in an electrical circuit. There are three types of multimeters made available in the market such as: digital multimeter, analog multimeter and fluke multimeter.

The Following are used for Testing Stimulus Signals of the Circuit Under Test

Power Supplies

A power supply is an electronic instrument that supplies electric energy to an electric load. Regulated power supplies refers to a power supply which supplies a variety of output voltages used for bench testing of electronic circuits, with the variation of output voltages or some preset voltages. Almost all the electronic circuits make use of a DC source of power for operation. A regulated power supply consists of various blocks such as an ordinary power supply and a voltage regulating device. The output generated from ordinary power supply is fed to the voltage regulating device that provides the final output. The main function of a  power supply is to convert one form of electrical energy into another.

Signal Generator

A signal generator is also named as pitch generator, function generator or frequency generator is an electronic device used for generating electronic signals either in the analog or digital domains (repeating or non-repeating signals). Signal generators are used in testing, designing and repairing electro acoustic or electronic devices.

In general no electronic device is suitable for all applications. There are various types of signal generators with different applications and purposes. During the development in technology, compared to signal generators there are flexible and programmable software tone generators with embedded hardware units are made available in the  market.

Pulse Generator

A pulse generator is either an electronic circuit or a piece of electronic test equipment used to generate electrical pulses in different shapes: mostly used for tests at analog or electrical level. Pulse generators are used to control the width, frequency,delay based on the low and high voltage levels of the pulses and  with respect to an internal and external triggering. There are three types of pulse generators namely optical pulse generator, bench pulse generators and microwave pulsers.

Digital Pattern Generator

A digital generator is an electronic testing equipment or software used to generate digital electronics stimuli. Digital electronics stimuli are  a specific type of electrical waveform varying between two conventional voltages corresponding to two logic gates (either 1 or 0, low or high).  The function of the digital pattern generator is to stimulate the inputs of a electronic device. For that purpose, the voltage levels are generated by a digital pattern generator are compared to I/O standards of digital electronics: TTL, LVTTL and LVDS. It is also known as a logic source because it is a source of synchronous digital stimulus.

It generates a signal for testing digital electronics at logic level. This  generator also produces a single shot or repetitive signals in which some sort of triggering source takes place ( internally or externally)

The Following Equipments Analyze the Response of the Circuit Under Test

Oscilloscope

The oscilloscope is an electronic test instrument that constantly obverses varying voltage signals as a two dimensional plot of one or more signals as a function of time. The other names for oscilloscope are oscillograph, cathode ray oscilloscope or digital storage oscilloscope. It is also used for converting non electrical signals such as vibration or sound into voltages and then displays the result.

Oscilloscopes are used to observe the change of an electrical signal based on time such that voltage and time describe a shape of the signals and graphed continuously compared with a calibrated scale.The obtained waveforms can be considered for following properties such as frequency, amplitude, time interval, rise time and others. Modern digital instruments may calculate these properties directly and displays them.

Frequency counter

Digital frequency counter is an electrical test equipment used for measuring the frequency of repetitive signals and elapsed time between events.  Digital frequency counters are also used to measure the radio frequency where it is important to measure the precise frequency of a particular signal.

There is a slight difference between the timers and frequency counters in the electronic industry. It is often possible to use both timers and frequency counters to perform the both functions: to measure the time and frequency. Frequency counters are mostly used as general purpose laboratory test equipment to measure higher frequencies.

Advanced or Less Commonly used Testing Equipment

LCR Meter

LCR Meter name itself indicates that it is used to measure the inductance, capacitance and resistance of electronics components. The inductance, capacitance and resistance are denoted by the letters L, C, and R so it is named as LCR Meter. A variety of meters are made available in the market, but simple versions of LCR meters indicates impedance only for converting the values to capacitance or inductance.

More designs are available and used to measure the capacitance or inductance, and also the equivalent series resistance of capacitors and the Q factor of inductive components. These conditions make the LCR meters valuable for measuring the quality and overall performance of the component.

There are many advanced testing equipments developed using most innovative technologies and are being used almost all types of electrical and electronic industries for checking estimated results and operation of electronics projects or devices. For more information regarding the testing equipments and their working you can contact us by posting your queries in the comments section below.

Photo Credits:

• Ohmmeter by wikimedia
• Ammeter by 12volt
• Power Supplies by directindustry
• Signal Generator by bilkent
• Pulse Generator by photonicsolutions
• Digital Pattern Generator by directindustry
• Oscilloscope by microcontroller-projects