Work on resistance measurement, described in An Elementary Treatise on Electricity, helped pave the way to successful trans-Atlantic telegraphy. In Part 1, I discussed An Elementary Treatise on Electricity by James Clerk Maxwell. One volume made national news earlier this summer when it was returned to New Bedford, Mass. Free Public Library 115 years overdue. […]
FAQ
That Maxwell book that was returned to a library 115 years late: what’s it about? (Part 1)
Published in 1881, An Elementary Treatise on Electricity evolved from notes Maxwell had written in preparation for lectures on electricity at the Cavendish Laboratory. In June 2023, the national media carried a story about a book 115 years overdue that was returned to the Free Public Library in New Bedford, Mass. The book turned out […]
What is PCIe gen 6 and how do I test it? Part 2
PAM4 modulation boosts throughput but adds test challenges. Part 1 of this two-part series described the evolution of the PCI Express (PCIe) standard, including the move from non-return-to-zero (NRZ) signaling in PCIe 5 to four-level pulse-amplitude modulation (PAM4) signaling in PCIe 6. What unique test challenges does PCIe 6 present? As mentioned in Part 1, […]
What is PCIe gen 6 and how do I test it? Part 1
PAM4 modulation boosts throughput but adds test challenges. The Peripheral Component Interface (PCI) emerged in the 1990s as a parallel bus for connecting computer mainboards and peripheral devices. In 2003, a serial version called PCI Express (PCIe) debuted, with generation 1 offering a transfer rate of 2.5 GT/s. Over the past 20 years, successive generations […]
How does a thermocouple work, and do I really need an ice bath (part 2 of 2)?
Modern thermocouple instruments automate the cold-junction-compensation process. Part 1 of this two-part series introduced thermocouple cold-junction compensation (CJC). This part will elaborate on the concept. Table 1, presented in part 1 and repeated here, lists a subset of the NIST voltage and temperature data for the type T thermocouple.Figure 1 shows a typical measurement setup, […]
How does a thermocouple work, and do I really need an ice bath (part 1 of 2)?
Efforts at the Bureau of Standards 110 years ago paved the way for the cold-junction-compensation technique used today. Thermocouples have long been used to make temperature measurements. They are simple, consisting of a pair of wires of dissimilar metals welded together at one end. They are rugged, operate over wide temperature ranges, and generate readily […]
What is jitter and what can I do about it (part 2 of 2)?
Operations on acquired jitter data help quantify jitter values. Part 1 of this article described the oscilloscope eye diagram and unit interval (UI) and focused on a single ideal rising edge with 28 additional edges representing some degree of jitter (Figure 1). We determined the peak-to-peak jitter to be 15 ps, based on the edges […]
The factors of accurate measurements
All measurements need reliable, accurate equipment that’s traceable to worldwide standards. Without that, measurements have no value. From ensuring product quality in a factory to safety to letting every individual use a computer or phone, accurate measurements are critical in every aspect of our lives. In the automotive industry, accurate measurements of components and the […]
What is jitter and what can I do about it (part 1 of 2)?
Measuring and quantifying jitter are the first steps toward controlling it. Jitter is a measure of the timing performance of a digital data stream such as Ethernet, USB, PCIe, or HDMI. It defines when data transitions occur in relation to an ideal waveform. Excess jitter can lead to signal-integrity problems that result in high bit-error […]
Automate double-pulse testing in WBG devices
By automating double-pulse testing of wide bandgap devices such as SiC and GaN power devices, you can cut setup and analysis time. The need to reduce carbon emissions drives investments in electrical technologies, particularly in data centers and electric vehicles. In its most recent Elective Vehicle Outlook report, Bloomberg estimates a 27% increase in global […]
