I enjoyed Dan Heberts recent article A Too-Smart Solution? (Technically Speaking, August 2007). It seems at times we cant see the forest for the trees. Its often true: Simple solutions are all that are needed, and therefore as you stated, simplicity is a virtue.
I, too, am a participant in SCEs curtailment program. I have yet to experience a cut-off, even in hot Temecula; yet I have experienced the lower bill. So Im pretty pleased at this point.
VP Marketing, Opto 22
I was very disappointed when reading you article Level Measurement: The Very Last Resort (August, 2007) that I did not find magnetostriction in Figure 1. I went back and read your First the Application, Then the Product article from the February 2007 issue. I could not find any reference to magnetostriction. Why did you leave out magnetostriction? As a manufacturer of gauges that use magnetostriction technology the lack of coverage concerns me.
Product Marketing Manager
Magnetostrictive devices are indeed in the chart, along with all the other mechanical level measurement devices. Magnetostrictive devices use a float to cause magnetostriction at the location of the float, and produce a signal that indicates the level in the vessel. Other float-type level devices use sensing elements other than magnetostriction, but they all have similar applications and similar installation challenges. In the chart referenced in Mr. Aikens letter (insert chart url) the first bar is mechanical devices. Thats where magnetostrictive level devices belong. So, no, we didnt leave out magnetostriction, and it is not a special category of device that requires mention by itself. Ive used magnetostriction level sensors, and I recommend them where they will perform in the optimum manner.
Who Owns What?
I always enjoy reading the monthly Control magazine. I was reading the last page of the July issue and have a suggestion for Keith and you. He points out how hard it is to keep up with who owns what nowadays in the instrumentation world, and I fully agree. Ive often thought it would be nice to have a timeline of who bought what and when. In my nearly 30 years as an instrument engineer Ive seen lots of companies come and go. Some of them made some really great products. How about Control putting together a timeline like this?
David Land, PE
Thanks for your kind words. We havent built a timeline, but look for our Directory of Lost Companies wiki, soon to appear at www.controlglobal.com. Were seeding the wiki with the names of the nearly 200 lost companies we know about. Then its up to readers to fill in the blanks.