Vol.4 No.2 Subject: Flow Measurement News Date: 2-13-01 From: McCrometer, "The Flow Measurement Specialists" ........ <<http://www.mccrometer.com>> ........ ******************************************* This newsletter is e-mailed by McCrometer monthly to subscribers worldwide. It consists of flow measurement information of interest for professionals in this field. For More information on our complete line of flowmeters go to: <http://www.mccrometer.com> ******************************************* How Magmeters Work Since their introduction in the 1950s, magnetic flowmeters, or magmeters as they are more commonly known, have become popular for measuring liquid flows. Here, we review how these meters work and look at some installation parameters users need to consider for optimum flowmeter performance. Magmeters work by using two magnetic coils to generate an electromagnetic field inside a straight section of pipe. As conductive liquid flows through the pipe, a voltage is created via Faraday's Law of Magnetic Induction. This voltage is measured by electrodes inserted through the pipe liner into the flow, and converted to a flow rate reading by the magmeter's signal converter. With their non-invasive measurement method, magmeters are perfect for metering difficult flows, such as highly corrosive or erosive liquids, fluids with a high percentage of solids, and fluids containing stringy solids, for example the twine or tumbleweed frequently found in raw sewage. All liquid flows must meet the minimum fluid conductivity required of not less than 5µS/cm, which includes all water and water-based slurries. Magmeters gained a reputation for reliability and low maintenance early on, because they have no moving parts to replace or maintain. They have also proved very versatile, with a wide rangeability of up to 1500:1. When selecting a magmeter, users should pay close attention to the type of liner used. For the most abrasive and corrosive applications, consider an epoxy-coated liner, rather than a traditional hard rubber of urethane liner. And for optimum measurement accuracy, select a magmeter that users full-field magnetic coils, instead of partial-field or insertion-type meters. For more information on McCrometer's line of magmeters, contact McCrometer at 951-652-6811 or visit our web-site at www.mccrometer.com. ******************************************* Copyright 2002 McCrometer ******************************************* Know anyone looking for a steady dose of flow measurement information? ******************************************* To subscribe send e-mail to <mailto:news-request@mccrometer.com> with a keyword SUBSCRIBE in the subject field. To unsubscribe, send e-mail to <mailto:news-request@mccrometer.com> with a keyword REMOVE in the subject field. ******************************************* To subscribe or unsubscribe online, please go to our website at: <http://www.mccrometer.com/subscribe.htm> ******************************************* Distributed by McCrometer "The Flow Measurement Specialists" <http://www.mccrometer.com>