A Practical Guide to Particle Counting for Drinking Water Treatment - Chapter 21 pptx

... most of the standard SCADA optomux drivers are incomplete and must be modified to accommodate it. Any of the manu- facturers may have developed an interface for a particular SCADA package, so it never ... require a little more effort to clean and maintain, and a particular style of software presentation may be more suited to a given set of operators. Although it is becoming les...

Ngày tải lên: 18/06/2014, 19:20

... Data Broadwell, Mike A practical guide to particle counting for drinking water treatment/ Mike Broadwell. p. cm. Includes index. ISBN 1-5 667 0-3 0 6-9 (alk. paper) 1. Particle counting (Water treatment ... D.C. A Practical Guide to Mike Broadwell for Particle Counting Drinking Water Treatment © 2001 by CRC Press LLC 6 A PRACTICAL G...

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... Packaged Treatment Plants Packaged treatment plants, as touched on above, are prefabricated plants, which are more cost-effective than ground-up plants for smaller applications. A packaged plant ... removal. (Courtesy of Pacific Scientific Instruments, Grants Pass, OR.) 28 A PRACTICAL GUIDE TO PARTICLE COUNTING manufacturers of packaged treatment plants employ particle c...

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... at a time. If a spare is available it can be rotated into service. The maintenance log should be kept up- to- date, and calibration stickers displaying the date of calibration placed on each particle ... practical. 2. Particle Counter Calibration Verification Verifying calibration is an easier and more practical step for the water plant operator. Only a couple of partic...

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... PRACTICAL GUIDE TO PARTICLE COUNTING The disadvantage to this approach is that the particle counter data are collected and displayed separately from the other plant data, requiring separate training ... second alternative is the direct interface of the particle counters to SCADA using serial data communications. All count data, as well as status and alarm information, are t...

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... case of online particle counting, trending the grab-sample data with other plant parameters will add to its value. If these data are available in a usable file format that can be imported into ... prior to each use. Certainly an acid washer and particle- free storage area would be ideal, but these are usually not necessary for 2- m particle counting. It is a good idea to k...

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... detected and measured if it produces a signal with a minimum 2 to 1 signal -to- noise ratio. B. SIGNAL -TO- NOISE RATIO All electronic instruments are subject to various forms of “noise,” or random, meaningless ... mentioned is Section A, the smallest particle that can be reliably measured must produce a signal amplitude at least twice that of the noise, or a 2 to 1 signa...

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... 82 A PRACTICAL GUIDE TO PARTICLE COUNTING The cell window materials vary in optical quality. Small imperfections in the material diffuse the light and are a source of resolution and sizing ... reflected back into the laser, it can disrupt this process, and cause variations in the beam intensity. This is another reason that aluminum flow cells are anodized a dark color, as the...

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... called a voltage comparator input stage. The more complex approach involves analog -to- digital (A/ D) conversion. 1. Voltage Comparator A comparator is simply a small circuit that “compares” an ... typically communicated every minute. The comparator provides a simple way to convert the particle size information from an analog pulse to a digital count value. It is a very...

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... voltage range of a chart recorder or SCADA analog input is 1 to 5 V. A 250 Ω resistor is required to convert a 4 to 20 mA signal into a 1 to 5 V signal. Another benefit of the 4 to 20 mA current ... some cases, flow alarms can be signaled by the particle counter via the computer data collection system. A. DIAGNOSTIC SIGNALS, ALARMS, AND DISPLAYS The most common alar...

Ngày tải lên: 18/06/2014, 19:20