Yes, Paul, and I requested this correction a few weeks ago when another reader noted the incorrect units. Sometimes symbols don't translate well from a Word document to the HTML. I'll ask again--thanks for your reminder.
Hi, Christopher. You make a good point about sensor ranges, so I'll put it on my topic list for a column after I wrap up this series on data-acquisition. You remind me that it's always good to start on a high range with an instrument and then change to a lower scale as appropriate. I once saw a bent needle on a Simpson VOM someone used to measure line power with a low-voltage setting. It almost made me cry.
Glad to see you presenting this. I've often had to point this out to my junior engineers; now I can point them to this article.
On a parallel subject. Are you going to discuss selecting sensor ranges relative to the measured value in question? I've also encounter situations where the engineer selected something like a 0-100 psi pressure transducer to measure a varying pressure with a mean around 80 psi and then just assumed the occasional 100 psi spikes where as high as the signal got.... I was trained to select a sensor which put the nominal reading at ~50% of the sensor range if I was fairly sure of what I was measuring, and to use less of the range if there was more uncertainty in the measured quantity.
The first Tacoma Narrows Bridge was a Washington State suspension bridge that opened in 1940 and spanned the Tacoma Narrows strait of Puget Sound between Tacoma and the Kitsap Peninsula. It opened to traffic on July 1, 1940, and dramatically collapsed into Puget Sound on November 7, just four months after it opened.
Noting that we now live in an era of “confusion and ill-conceived stuff,” Ammunition design studio founder Robert Brunner, speaking at Gigaom Roadmap, said that by adding connectivity to everything and its mother, we aren't necessarily doing ourselves any favors, with many ‘things’ just fine in their unconnected state.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.