Tag Archives: Test & measurement

Testing a mysterious instrument

By Michael D. Allen – My first job after leaving school was that of an associate engineer. This meant that I was half technician and half engineer, and I would design something and then build and test it. Because of this position, I frequently got some odd and interesting jobs.

One day a cardboard box showed up on my bench with a test box, a bunch of blueprints, a test procedure, and an “angle of attack” aircraft instrument. Management told me to grab an inspector, perform a functional test on the instrument, and buy off on all of the steps. This was the first aircraft instrument that anyone had seen in our lab area.

There were no program identifiers on the blueprints, the test box, or the instrument itself. I had no way to compare the numbers on the blueprints to any program. If anyone knew what the associated program was, he wasn’t telling.

The instrument was connected to the test box and turned on. A given DC input was supposed to drive the needle to a certain location on the dial face. This worked to a certain extent; the needle would drive to the commanded location but overshoot, back up, and overshoot again. The needle would be a blur, oscillating around the commanded location.

The test box was checked and appeared to be working correctly. Because the instrument was not working correctly, I ask the inspector if it would be OK to open it up to see what was inside, and he agreed. The instrument had a can extending several inches beyond the back of the dial face. The can had a sealed connector and a purge port to refill it with nitrogen. The inside of the instrument looked like several pocket watches stacked together. more>

Supersonic Flight is Back

The 1970s Concord supersonic transport has been re-imaged by Boom Technology with an eye for the modern business traveler.
By John Blyler – The supersonic phoenix is rising again. The latest incarnation of faster-than-sound flight for the commercial market is being created by Boom Supersonic, the aerospace startup company. Boom recently announced that its supersonic demonstrator, XB-1, will roll out on October 7, 2020.  XB-1 is an independently developed supersonic jet and that will demonstrate key technologies for Overture, Boom’s commercial airliner, such as advanced carbon fiber composite construction, computer-optimized high-efficiency aerodynamics, and an efficient supersonic propulsion system.

Boom Technology’s co-founder and then VP of Technology, Joshua Krall, was a keynote speaker at Dassault Systemes’s annual 3DExperience Forum in 2019.

“Our goal is to make high-speed travel available to everyone – not just the thrill seekers or rich travelers,” explained Krall at the forum. “It not so much about time saved but about life gained back from faster air travel.”

For all but the wealthiest travelers, the promise of a supersonic adventure never arrived. The last supersonic aircrafty was the British-French turbojet powered Concorde which operated from 1974 until 2003. It had a maximum speed over twice the speed of sound, at Mach 2.04 (1,354 mph or 2,180 km/h at cruise altitude). Most of today’s commercial jet aircraft reach around 400 – 500 knots (460 – 575 mph) or roughly 0.6 mach. The mach number is simply a percentage of the speed of sound. At sea level with an air temperature of 15 degrees Celsius, the speed of sound is 761 mph.

There are zero scientific barriers to supersonic flights, said Krall. However, there are cost barriers. Boom hopes to bring the reduce the cost barrier for supersonic flight. It plans to do so with Overture, the first Boom aircraft for commercial use. Overture will travel at mach 2.2 or approximately 2.6 times faster than existing commercial jet aircraft. It will cruise at 60K feet, about twice as high as commercial aircraft. more>

Updates from Datacenter.com

If you don’t test your back-up power, don’t expect it to work!
Datacenter.com – Last week we again conducted a black building test. This time including the power expansion which will be active soon. We always have full confidence in our black building test, but it’s good to test this regularly. After a series of power outages at various data centers, we ensure there is a power supply when you really need it.

If the power goes out for a short or long time, that is of course annoying if your favorite TV show was just on TV. But if a power outage means that your critical IT infrastructure no longer works, there are far-reaching consequences for your company. How is a power outage picked up by Datacenter.com.

For companies, organizations and governments, reliable power supply is one of the most important reasons for placing their IT equipment in a data center. Recent high-profile data center failures brought the issue of reliability to the fore. Historically, data center power cuts have been experienced by many blue-chip banks and telecoms providers, so no-one can claim immunity from such problems.

To guarantee the reliability of that power supply, we test our emergency power supply on a monthly basis. During such a test, we activate the generators to ensure the redundant power supply path works appropriately. By setting up a switch that starts our redundant set of emergency power supply, synchronizes with the mains, and delivering power to the IT equipment. During regular generator tests, the generator is putted next to the grid so the equipment that is not behind UPS remains switched on. This means that the cooling system and the lighting will continue to work during such a test. more>

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Eye diagrams: The tool for serial data analysis

By Arthur Pini – The eye diagram is a general-purpose tool for analyzing serial digital signals. It shows the effects of vertical noise, horizontal jitter, duty cycle distortion, inter-symbol interference, and crosstalk, all of which can close the “eye.” While engineers have used eye diagrams for decades, oscilloscopes continually get new features that increase its value.

Oscilloscopes form eye diagrams—the separation between the two binary data states “1” and “0”—by overlaying multiple single clock periods on a persistence display. The accumulation shows the history of multiple acquisitions.

Additive noise tends to close the eye vertically while timing jitter and uncertainty closes the eye horizontally. Duty cycle distortion (DCD) and inter-symbol interference (ISI) change the shape of the eye. The channel will fail if the eye closes to the point where the receiver can no longer recognize “0” and “1” states.

In the days of analog oscilloscopes, the eye diagram was formed by triggering the oscilloscope with the serial data clock and acquiring multiple bits over time using a persistence or storage display. This technique adds the trigger uncertainty or trigger jitter to the eye diagram for each acquisition. Digital oscilloscopes form the eye by acquiring very long record with many serial bits.

The clock period is determined, and the waveform is broken up or “sliced” into multiple single-bit acquisitions overlaid in the persistence display. In this way, all the data is acquired with a single value of trigger jitter that’s eliminated by using differential time measurements within the eye. more>

Commercializing 5G: How to use standards and testing for success

By Kalyan Sundhar – The standards that dictate how 5G systems should work and interoperate were released earlier this year from the Internet Engineering Task Force (IETF) in an eagerly awaited update. The new telecommunications standards cleared the way for those planning to develop, build, or leverage 5G technology.

It is clear that a great deal of thought went into the development of the latest versions of the 5G standards to spur the growth of the 5G market and deliver new opportunities. Technology that follows these standards will ensure that the reliability of these networks is much more stable as it fills in the new market gaps.

This new version of the standards has opened the door for stand-alone (SA) 5G networks that do not rely on 4G for 5G signaling and kicking off a frantic rush to own the 5G market. While 4G networks are still available for added support, companies that do not have an existing 4G infrastructure can build their 5G deployments from scratch. This is due to a section of the standards that governs 4G handovers through interweaving 5G cells with existing 4G deployments.

The standards are only the foundation that will support the development of the 5G industry, but there is still plenty of work needed by companies to get it right. What that will look like is up to individual interpretation as there are gaps in the guidelines that make up the new standards. Interoperability will continue to be a challenge as organizations implement proprietary visions for 5G within those gaps. more>

How To Improve Results With The Right Frequency Of Monitoring

By George Bradt – Most understand the need to follow up and monitor progress on a theoretical level. Yet there are few guidelines to how frequently you should do that. Let me suggest that varies by the nature of what you’re monitoring, ranging from daily or even more frequently for tasks to annually for strategic plans.

Ben Harkin discussed the value of monitoring and reporting in the Psychological Journal. His headline is “Frequently Monitoring Progress Toward Goals Increases Chance of Success” – especially if you make the results public. While he was more focused on personal habits and goals, the findings are applicable to organizational behavior as well.

Here’s my current best thinking on the right frequency of monitoring. The main discriminant is the nature of the work and level of people doing the work with tighter, more frequent monitoring of tactical efforts and looser, less frequent monitoring of more strategic efforts.

  • Daily or more frequently – Tasks
  • Weekly – Projects
  • Monthly – Programs
  • Quarterly – Business Reviews, adjustments
  • Annually – Strategic/Organizational/Operational processes

more>

X-rays from Copper Source Set New Gold Standard for Measuring Industrial Materials

By Alison Gillespie – Researchers at the National Institute of Standards and Technology (NIST) have produced and precisely measured a spectrum of X-rays using a new, state-of-the-art machine. The instrument they used to measure the X-rays took 20 years to develop, and will help scientists working at the agency make some of the world’s most accurate measurements of materials for use in everything from bridges to pharmaceuticals.

The process of building the instrument for making the new measurements was painstaking. “This new specialized precision instrument required both a tremendous amount of mechanical innovation and theoretical modeling,” said James Cline, project leader of the NIST team that built the machine.

“That we were able to dedicate so many years and such high-level scientific expertise to this project is reflective of NIST’s role in the world of science.” more> https://goo.gl/e0zrET

How Ethernet Will Get to 400Gbps

By Lynnette Reese – The IEEE 802.3bs standard for 400Gbps is on track to be ratified and released late this year. Higher speed technologies tend to get driven to adoption as soon as they are available.

In 2004, 10Gbps was the leading edge. In 2010 40Gbps Ethernet and 100Gbps were introduced. How did we get this far, so fast?

The present group is leveraging a parallel lane structure to get to 400Gbps. For electrical interfaces the fastest speeds in the spec will be 50Gbps. When discussing optical fiber transmission, then the variation depends on the distance that one requires.

Technically, 400Gbps is not possible without switching away from non-return-to-zero modulation (also known as NRZ-type) encoding, the encoding scheme that everyone thinks of when they visualize Ethernet communication and other serial data transmission schemes.

NRZ data is encoded into a binary pattern with fixed voltage levels. A binary 0 is represented by the lower voltage level; the higher voltage level indicates binary 1. In 1000base-T Ethernet, the stream of 0s and 1s is driven at a 1000 bits per second (1Gbps) transmission rate.

At present, the physical “wall” of streaming 0s and 1s for single lane electrical interfaces is 25 Gbps, found in the standards as 802.3bj across backplanes and cables, and 802.3bm across chip-to-chip and chip-to-module interfaces.

In May 2016, an IEEE 802.3 task force formed to develop a single-lane 50 Gbps Ethernet standard. The 802.3bs standard, which defines 400Gbps in aggregate, will use an encoding scheme called PAM4 (4-Level Pulse Amplitude Modulation) to reach 50Gbps per channel. PAM4 is an encoding scheme that doubles the bit rate by providing four signal levels in the space of the two that NRZ presently provides. PAM4 cleverly divides the least significant bit (LSB) signal level in half and adds it to the signal of the most significant bit (MSB). more> https://goo.gl/fcDF8f

Developing the APTitude to Design New Materials, Atom-by-Atom

By Paul Blanchard – Up to now, our technological progress has largely been a matter of trial and error. We make something new, evaluate its performance, then alter some part of the fabrication process and see whether it performs better or worse, all without direct knowledge of what is changing at the atomic level.

But if we could see what’s going on at that scale—if we could map out each individual atom and understand the role that it plays—we could create new and better materials not through blind experimentation, but through design.

For all that we’ve been able to accomplish while ignoring them, the fact is that individual atoms matter. The speed of a transistor, the efficiency of a solar cell, and the strength of an I-beam are ultimately determined by the configuration of the atoms inside. Today, new and improved microscopy techniques are getting us closer and closer to the goal of being able to see each and every atom within the materials we make—a very exciting prospect.

Over the past three years, I’ve been lucky enough to be part of a team working with one such new and improved microscopy technique, a method called 3-D atom probe tomography, or APT for short. APT is very different from conventional microscopy—at least, the sort of microscopy that I’m accustomed to. In conventional microscopy, we shine a beam of light particles or electrons on our specimen, whatever it is we want to look at, and create a magnified image using lenses or by mapping how our beam bounces off it.

In atom probe tomography, on the other hand, we don’t just look at our specimen—we literally take it apart, atom-by-atom. more> https://goo.gl/c0VdE3

Updates from GE

This Ship Has Sailed: U.S. Navy Commissions An All-Electric Stealth Destroyer Zumwalt For Service
By Tomas Kellner – The U.S. Navy has commissioned for service the USS Zumwalt, its largest and most advanced stealth destroyer. The ceremony took place in Baltimore on Saturday (Oct 15).

The Navy estimates the 15,600-ton vessel can hit a target at a range of more than 60 miles. It also has a wave-piercing tumblehome design and a unique superstructure that make it less visible to enemy radar at sea.

The ship is equally innovative below deck. Traditionally, the Navy powered its vessels with gas turbines driving controllable pitch propellers through large and complex gearboxes. But the new destroyer has on board a 78-megawatt power station supplying electricity to an advanced integrated power system (IPS). GE Marine designed the system, which powers giant GE induction motors connected directly to the propeller shafts and routes electricity to a vast array of sensors, weapons, radar and other critical systems on board.

As a result, the ship will have nearly 10 times as much available power as its predecessors. In fact, the Zumwalt could become the first ship carrying next-generation weapons such as electromagnetic railguns, which use a strong electromagnetic pulse, rather than gunpowder, to shoot projectiles. “We’re no longer restricting the engines to provide propulsion power only,” Adam Kabulski, director for naval accounts at GE Power Conversion, told GE Reports.

“This design allows you to send electric power wherever you need it. You can access many megawatts in a short amount of time and convert it into energy. It’s instantaneous.”

The system is also highly redundant. Instead of the typical three-phase motors, the Zumwalt’s advanced induction motors have 15 phases. Kabulski said that by simply reversing the direction of the rotating magnetic field in the motor, for example, the shaft can turn in the opposite direction to give astern power. more> https://goo.gl/9WVdnz