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.
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