Test & Measurement

Martin Rowe
Senior Technical Editor
Technical information about test and measurement equipment and strategies from the point of view of the R&D or design and development engineer. Topics include T&M hardware such as oscilloscopes and signal generators/analyzers, as well as software and test methodologies.

Compact power meters boast 0.1% accuracy

Yokogawa’s WT300E series of digital power meters provides low-current measurements down to 50 µA and a maximum of up to 26 A RMS. Read More...

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Circuit remotely adjusts PSU voltage

This DI circuit allows for remote regulator/PSU programmability or trimming. Read More...

Programmable-gain amp achieves high gains

Roll your own PGA to get the exact high gains you need. Read More...

Fast, low-noise JFET amp is stable over temperature

This Design Idea combines the strong points of JFETs and CFAs to make a high-impedance amplifier that’s fast, stable over temperature, and quiet. Read More...

AC power measurement uses PWM & PAM

Use clever pulse modulation techniques to multiply signals and measure power. Read More...

Simplified kurtosis computation detects signal interference

The statistical kurtosis operation, reinterpreted and implemented on an FPGA for this Design Idea, can detect various forms of interference in RF and other signals. Read More...

De-embed transmission lines with FIR filters

This DI uses MATLAB to design de-embedding filters which clean up high-speed signal measurements. Read More...

Instrumentation amp makes an accurate transimpedance amp too

The interesting topology in this Design Idea turns a monolithic in-amp into a good transimpedance amp for photodiode or similar applications. Read More...

Transient load gives power systems a workout

Verify power supply performance with this transient load generator. Read More...

Bad-bulb finder fixes Christmas lights

15 years later, here’s a new take on one of our most popular Design Ideas ever! Read More...

Power transient buffer enables IC & circuit testing

This DI lets you use a versatile function generator to test a circuit’s response to power transients and noise. Read More...

Antilog converter linearizes carbon dioxide sensor

Simplify gas sensor interface with some analog preprocessing. Read More...

Sub-picofarad measurement with CMOS inverters

Measure capacitance down to 2.5pF full-scale using this hex inverter-based design. Read More...

Short circuit tracer/finder uses low power

Build this bench tool and become a master at pinpointing shorts. Read More...

LabVIEW real-time seismic alert system

National Instrument’s LabVIEW has uses beyond instrument control, as demonstrated by this Web app. Read More...

LTC Design Note: Robust 10MHz reference clock input protection circuit and distributor for RF systems

Design a protected 10MHz reference input without degrading phase noise. Read More...

Milliohm Squawker great at finding shorts and reverse engineering PCBs

This well thought out tool for “listening to” low resistances really speeds troubleshooting & tracing. Read More...

Versatile noise generator tests signal recovery gear

Accurate noise generator allows mixing-in of a clean test signal. Read More...

LTC Design Note: Measure RH with instrumentation-grade system monitor

An accurate, modern system monitor chip senses humidity the old-fashioned way. Read More...

Simple capacitance meter bins parts

This simple, elegant circuit lets you quickly sort through capacitors. Read More...

Detect wire breaks with unusual CMOS gate circuit

TDR in the shop? Try this circuit to detect a wire break. Read More...

Measure inductance & capacitance over a wide range

Measure inductors and capacitors over a very wide range of values with this simple circuit. Read More...

Best Design Ideas of 2013Q3

We present the best Design Ideas of the last quarter! Read More...

Precision capacitance meter

There's an art to capacitance measurement. What do you think of this rendition? Read More...

Novel Q-meter

This highly unusual "cross-quad" circuit topology finds application measuring Q. Read More...

Voltage-to-period converter improves speed, cost, and linearity of A-D conversion

Turning a VFC on its head improves many parameters. Read More...

Complete, low-cost, software programmable ohmmeter measures micro-ohms

An ac voltage is generated by switching current into the unknown resistance. The resulting ac voltage is then amplified and filtered to produce an output voltage proportional to the resistance being measured. Read More...

Convert your smartphone into a pedometer and tracking device

A bit of Python code along with the power of GPS and your smartphone lets you track and record your outdoor excursion activities. Read More...

Photo meter assesses ambient light

When most PN-junction diodes are reverse biased, they will produce a small photovoltaic output as the light level is increased. Read More...

Circuit automatically switches off DMM

Add automatic-shutoff to your DMM, save batteries, and eliminate wear and tear on the function switch. Read More...

Create secondary colors from multicolored LEDs

One disadvantage of generating a yellow color by mixing two primary-color light sources is that the LED must use twice the current because both the red and the green LEDs must be on. Read More...

Measure an amplifier's THD without external filters

Adding a secondary amplifier boosts the THD to measurable levels. Read More...

Wireless temperature monitor has data-logging capabilities

You can make a wireless temps system with two ICs. Read More...

Make an asynchronous clock for VPX-based PCIe systems

Careful crystal selection and an FPGA are key to success. Read More...

Use a photoelectric-FET optocoupler as a linear voltage-controlled potentiometer

The circuit takes advantage of an identical photo-FET as a feedback element. Read More...

Use air-core-coil resistance to estimate inductance

If the coil is tightly wound you do not need the number of turns to calculate inductance. Read More...

Current monitor uses Hall sensor

Use a Hall-effect sensor to measure dc current in the range of 0 to 40A. Read More...

Circuit provides more accurate multiplication

Convert into and out of the sampled-data domain to get an accurate multiplication. Read More...

Simple night-light uses a photoresistor to detect dusk

You can adjust this battery-powered circuit for different levels. Read More...

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Compact power meters boast 0.1% accuracy

Yokogawa’s WT300E series of digital power meters provides low-current measurements down to 50 µA and a maximum of up to 26 A RMS. Read More...

>> SEE ALL

The Tektronix 1101 oscilloscope-probe power supply

A mechanical design is at once a masterpiece and an expensive expedient. Read More...

What's inside a smart meter? iFixit tears it down

When iFixit's Kyle Wiens had the opportunity to tear down an Elster smart meter, he jumped at it—not to come up with a repair manual but to evaluate the health and safety issues that seem to surround the utilities’ installation of smart meters. Read More...

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Optimizing Arduino and the AD9851 DDS signal generator

Find solutions for the output amplitude and distortion issues that can plague the Analog Devices AD9851 DDS waveform generator Arduino module. Read More...

Temperature sensors are improving, but select carefully

Temperature sensors, from thermistors and thermocouples to RTDs, are ubiquitous, but designers would be wise to look closely at the characteristics of each before making a selection as improvements in both design and associated software and algorithms tend to change their respective advantages. Read More...

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Do grandmas make the best engineers?

Can big global problems be solved by grandmothers who are intent on solving small local problems? Read More...

Keysight enhances RF signal analyzers

Capacitive touch screens, emphasis on usability top the list of improvements to the company's X-series, which consists of five base models. Read More...

New test products at DesignCon 2016

Test & measurement is a significant part of DesignCon. Here are some new products, with live video demonstrations from the exhibit hall. Read More...

Find the settings and open the eyes

OptimEye from SiSoft reduces the laborious task of optimizing serial transmitters and receivers. Read More...

DesignCon 2016: 4 unexpected things

DesignCon 2016 was full of the usual high-speed signals, but these were things you wouldn’t expect to see there. Read More...

PAM4 challenges at DesignCon 2016

With the last word on PAM4, panel looks at how PAM4 will affect simulation, bench measurements, and production test. Read More...

NI’s enhanced version of VirtualBench on display at DesignCon

Developers have taken bench-top equipment to a whole new level with the latest, high-performance model of VirtualBench. Read More...

DesignCon Panel Highlights 25G, PAM4

The annual DesignCon "Closed Eye" panel highlighted what's happening with PAM4 modulation and its integration with Ethernet. Read More...

Top 6 modular instrument predictions for 2016

Larry Desjardin makes six predictions for 2016 affecting modular instruments and the test and measurement industry. Read More...

The actual father of electricity

You may think that Volta or Ampere would be credited with being the father of electricity, but not so. Read More...

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