Corrections – 2004-02-01

>> Power ‚ energy. Inadvertently, the units of energy and power (rate of using energy) were confused in the third- and second-to-last paragraphs of "Sugar mill is 'sweet' application for medium-voltage drive," Application Update, Control Engineering, Jan. '04, p. 9. Conclusions and payback figures remain unchanged.

By Staff February 1, 2004

>> Powerenergy. Inadvertently, the units of energy and power (rate of using energy) were confused in the third- and second-to-last paragraphs of “Sugar mill is ‘sweet’ application for medium-voltage drive,” Application Update, Control Engineering , Jan. ’04, p. 9. Conclusions and payback figures remain unchanged. The correct text follows:

“The previous turbine used 48 pounds of steam per hour for every kW of power, while the new, efficient electrical motor and drive system uses only 16.2 pounds of steam per kWh to provide 1,420 kW of electrical power.

Power consumption of the electrically driven mill is approximately 550 kW, leaving roughly 870 kW for sale to the utility. At US$0.055/kWh, this meant additional revenue of $158,480 in six months of harvest time…”

In other words, steam usage should have units of lb/kWh, not lb/kW; power generated/used should be kW, instead of kW/hr; and electrical cost should be $/kWh, not $/kW.

>>QSI Corp.’s Qterm-G70 graphics terminal with power over Ethernet technology was misspelled in the “Product & Software” section on page 49 and on the cover of Control Engineering , Dec. ’03.

>>A headline about Magnetrol International’s Eclipse Model 707 two-wire, loop-powered radar level meter was misspelled in Control Engineering ‘s Editors’ Choice Awards supplement, Jan.’04, p.S12. The headline should have read “Loop-powered radar measures interface, level.”