Elektor Community Perspectives on Test and Measurement
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Sebastian Westerhold (Baltic Lab) - Germany
Standards First: Don’t Copy Bad Measurement Practice
Read the standards that apply to the measurement you are performing. Relying on “experienced colleagues” or staying within the comfortable “I’ve always done it this way” mindset is a surprisingly reliable way to get it wrong. Standards evolve, and practices that were once acceptable, or that have simply become common within a community, do not automatically remain compliant. Widespread adoption does not equate to standards compliance.
A good example is the measurement of unwanted emissions, such as harmonics, from amateur radio transmitters in the EU. Despite the abundance of articles and videos on the topic, it is remarkably difficult to find one that actually follows the relevant standards correctly. This is not due to a lack of competence, but to copying what others do instead of reading the relevant standard (ETSI EN 301 783-1).
If the goal is meaningful, defensible measurements, there is no substitute for reading and re-reading the applicable standards.
Pieter De Villiers (Director, Teralec) - South Africa
Motor Insulation Testing: Why a “Megger Test” Isn’t the Full Story
A recurring issue in motor testing is not the insulation tester itself, but how it is used. These instruments are often referred to as “Meggers,” but that term is actually a brand name; the correct, generic description is an insulation resistance tester. They are commonly used to check motor insulation, among other applications.
In the field, a typical routine is to test each phase to earth and then conclude that “the motor is fine.” At best, that conclusion is incomplete. The test can be performed more thoroughly, and insulation resistance is only one element of a proper motor assessment.
A more informative approach is to remove the delta/star links and test each winding to earth, then test between windings as well. This checks insulation integrity to earth and helps reveal leakage paths between any two windings.
Even so, insulation resistance tests have limits. They cannot confirm that the windings are physically intact, nor reliably detect shorted turns (where a few coils within a winding are shorting together).
Adam Mulligan-Wilson (Adam’s Vintage Computer Restorations) - United Kingdom
Methodical Debugging Beats Guesswork
I test and debug a lot of prototype electronics in my role, and no matter how hard you try to ensure new designs are thoroughly reviewed, something usually slips through the net: a misread datasheet, a filter network you forgot to simulate, or that pesky TX/RX inversion on a transceiver IC. My advice is to start by listing your symptoms and plausible causes, then work methodically to isolate the issue. Keep things simple and remove variables wherever you can, because extra moving parts make diagnosis far more difficult.
If it’s an intermittent fault, try to replicate the conditions under which it occurs and narrow down which variable is triggering it. Suspect everything, especially the things you haven’t considered yet — even trivial, “random” factors can cause real problems under the right circumstances. Decent equipment makes this easier: a probe station, multimeter, and oscilloscope. They don’t need to be expensive, just reliable, and suitable for the job.
Kevin Hubbard (Author, Mastering FPGA Chip Design) - United States
Buy a Scope You Can Grow Into
Buying an oscilloscope should be like buying your first house: go over budget and buy more than you need today. That 2-channel, 50 MHz bandwidth scope might be fine for your problems right now, but it won’t be much help when you’re chasing SPI signal integrity issues tomorrow, or trying to understand why a “working” design occasionally glitches in the field.
Give yourself headroom in bandwidth, sample rate, memory depth, and channel count, because real debugging rarely fits neatly into two traces. You’ll want to watch power, clock, data, and an enable line together, trigger reliably on a rare event, and zoom in without the waveform turning into mush. A scope you can grow into makes troubleshooting faster, makes your conclusions more defensible, and stays useful long after the first project has moved on.
Eddie Aho (KISS Analog) - United States of America
Measure Your Measurement First
The fastest way to level up your measurements is to treat your setup as part of the circuit. Most “mystery” glitches are self-inflicted: ground leads acting like antennas, probe capacitance loading a high-impedance node, or a supply lead that’s effectively an inductor at the frequencies you care about. Start with the boring basics: use short ground connections (spring ground if you have it), minimize loop area, and always sanity-check the probe bandwidth/attenuation and compensation before you trust a waveform. If the signal is small or fast, stop using a 10 cm crocodile lead and then wondering why the trace rings like a bell.
Second tip: always cross-check with at least one other viewpoint. If you see “noise,” change one variable at a time: different probe, different bandwidth limit, different vertical scale, different grounding point, different timebase, different instrument. Use the scope’s math and FFT, but don’t worship them — verify with a known source and remember the front end has limits. And don’t forget the simplest diagnostic tool: measure the same node with the circuit off, inputs shorted, or with a dummy load. If the problem survives those changes, it might be real. If it vanishes, congratulations — you just measured your measurement.
Editor's Note: This article appears in Elektor May/June 2026.
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