The PrevEx, formerly the 670 series of analyzers, is Control Instruments’ Flammability Analyzer for Lower FlammableLimit monitoring. Its new name boasts its ability to prevent explosions and its new look adds flavor to the industrialenvironment. To top it off, it still solves all of the sampling, measuring, and reporting problems found in industrialprocess applications while promising accuracy, consistency, and reliability. The PrevEx allows you to protect yourinvestment: it keeps your facility, employees, and environment safe while increasing your productivity and eliminatingdowntime. Its accuracy surpasses that of any other analyzer, due to its unique flame temperature technology, deliveringthe highest degree of safety. This exclusive design is based on a sensing-flame concept that has since proven itself to bethe most reliable detection system in the industry. Unlike catalytic sensors that can become contaminated, give falsereadings or fail outright, the PrevEx has many impressive features to ensure unmatched safety, extreme accuracy, andultra-fast response time, even when sampling a mixture of several different flammable vapors. The PrevExFlammability Analyzer is efficient and economical, leaving you feeling confident in its performance. After all, amonitoring system is only as good as the sensor it employs! Read on to find out more of the PrevEx’s exclusive featuresand see how it truly prevents fires and explosions. Prevent

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The PrevEx Flammability Analyzer incorporates severalfail-safe features designed to ensure perfect safety underall conditions. In fact, the inherent design of the sensingflame technology is that the flame must always be onand the system working properly or an alarm is given.This leaves no problem undetected. Whether it is a lossof fuel, air, sample flow or power, a malfunction relay isautomatically tripped and the operator is notifiedimmediately of a status change. By contrast, catalyticsensors and other “indirect” measuring systems canbecome corroded, obstructed or poisoned, yet stillregister as normal. The alarm relays include warning,danger, fault, horn, service needed, and system undercalibration. These built-in relays guarantee completesafety and reliability, allowing for only true indicationson the meter. From a safety viewpoint, the sensing flametechnology has no equal. The PrevEx also exhibits a verystable zero with a calibration accuracy of less than 5%error per year. In recognition to the PrevEx’s inclusivefail-safe features, our flammability analyzer has receivedthe following approvals:

The essence of the PrevEx detection system lies in itsability to perform accurately under the demands of theindustrial environment. Industrial processes containcompounds that condense and contaminate a sensor. Withcondensation comes clogging, fouling, and poisoning,which restricts the sample flow to the analyzer,removing important elements from the sample stream.This results in an inaccurate reading. To combat thisproblem and assure a true sample, the PrevEx has acorrosion resistant, heated sample train through whichthe sample is delivered. The heat eliminates thatcondensation and withstands corrosive elements,leaving you with an accurate representation of yourprocess. To be doubly sure that you are receiving anaccurate reading free of contamination, the PrevExFlammability Analyzer collects the sample using anaspirator, driven by compressed air. There is no pump orblower; instead microprocessor control guaranteesconstant sample flow and pressure through the train,assuring you of the highest level of accuracy. To top itoff, even the sensor itself is free of poisoning fromvarious organo-metallics, halogenated hydrocarbons,silicones, or plasticizers. This reliable performance leavesyour plant safe and secure, avoiding unnecessarydowntime and frequent maintenance.

No CondensationYields True Sample

PrevEx DeliversUnmatched Safety

losionsPrevEx mounted directly

on process duct

Field pneumatic andelectrical connections made

at bottom of PrevEx

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Sensing Flame TechnologyThe PrevEx Flammability Analyzer contains a carefully meteredpilot, or sensing flame. It is a direct measure of the totalflammability of the sample, not to be confused with the industry’sFID. This flame burns continuously inside a small chamber ofthe sensor housing. Flammable vapors are drawn from the samplepoint into the chamber, where they are incinerated by the flame.A temperature detector measures the resulting change in flametemperature and transmits the information for display in % LFLformat. Should a problem of any kind arise the flametemperature must change and the control monitor always letsyou know immediately.

Universal CalibrationThe PrevEx gives consistent and reliable readings even when facedwith multiple or changing solvent concentrations. In fact, the PrevExFlammability Analyzer has the ability to read multiple solventformulations more accurately than any other sensor in the entireindustry, resulting in the least amount of detection error fromsolvent to solvent. This is due to the powerful universal calibrationfeature, made possible through the PrevEx’s sensing flametechnology. This technology provides the ability to accuratelymeasure solvent concentrations for an array of solvents, even thoughthe meter was calibrated on only one specific solvent. That’s rightwith the PrevEx there is no need for recalibration, giving youexcellent cross-calibration accuracy and ultimately eliminatingincorrect readings. So, there is no need to shut down your system orbuy multiple sensors to monitor various solvents simultaneously,with the PrevEx just one calibration offers protection withaccuracy for your present and future needs. In the graph below,each bar illustrates the response factor for a particular solvent. Formost combustible gases it ranges from 0.8 to 1.2 and for solventsfrom 0.9 to 1.1. The uniformity of the bars indicates UniversalCalibration.

DANGERFAULT

CONTROL INSTRUMENTSCORPORATION

WARNING HORN ZERO IGNITESPAN HEAT

When it comes to giving you early warning no otherdesign even comes close to the PrevEx’s less than1-second response time. This impressive response, whichis eight times faster than the industry’s average sensor,is due to the PrevEx’s direct mount design. Bymounting the sensor directly on the process ductwithout heat trace sample lines, pumps, or blowers, youeliminate the unpredictability of moving parts andshorten the sample path significantly. This radicallyreduces sample delivery time, while ultimatelyaccelerating response time. The PrevEx FlammabilityAnalyzers are readily accessible. They easily attach to awide variety of process walls and duct types and areunaffected by high process temperatures, makinginstallation and operation uncomplicated. Fieldpneumatic and electrical connections are easily made atthe bottom of the analyzer. If necessary, an optionalwall-mount design is available.

The PrevEx Flammability Analyzer’s all inclusivedesign is easily operated and maintained. The front panelincludes a complete set of status indicators and aneight-character alpha-numeric LCD display. Using justtwo pushbuttons, you can access all calibration,programming and diagnostic routines. And for completeaccess, contacts are also provided for two externalcontrol inputs. A window in the outer cover lets you seethe entire front panel. This is where calibrationadjustments can be initiated. Since the PrevEx comesequipped with solenoid valves for both zero and spantest gas, an integral microprocessor automatically makesall calibration adjustments for you. The window alsopermits non-intrusive local access; you simply shine aflashlight at photo-transistors to activate a commandmenu.To make operation even more efficient the PrevExcan be accessed remotely. You simply connect directly toyour PLC or a display meter in the operator panel throughthe built-in 4-20mA analog output. If you need true,two-way digital communication with remote control, thePrevEx provides a Modbus RS-485 serial port andoptional operator interface panels. This extremelyefficient process greatly reduces maintenance time. Ofcourse, all parts are readily available and quicklyreplaced when needed, so when you want to inspect orservice a unit the job is fast and easy.

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Efficient OperationReduces Maintenance

Direct Mount ProvidesFastest Response Time

Control Instruments Corporation has been engineering solutions to gasand solvent vapor monitoring problems since 1969. We work hard toassess your risks and carefully tailor a monitoring system to meet yourneeds. For detailed information, system specifications, and pricing, pleasecontact us today.

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25 Law Drive Fairfield, NJ 07004 USAp: 973•575-9114 f: 973•575-0013 e: sales@controlinstruments.com w: www.controlinstruments.com

Control Instruments Corporation

© Control Instruments Corporation 2003. All rights reserved. Control Instruments, PrevEx, and the Control Instruments logo are registered trademarks of Control Instruments Corporation. H7FTA101 rev B 3/03

The PrevEx Flammability analyzer consists of several models designedto fit your specific monitoring needs. All models monitor a number ofcommon vapors and are unaffected by processes as diverse as flexographicprinting and ceramic kilns. The first two industrial strength analyzers,the SNR675 running at 270ºC and the SNR674 running at 200ºC, aresuitable for the most demanding conditions of industrial monitoring, wherehigh flash point solvents, resins, and plasticizers may be present. Thenext model, the SNR672 running at 120ºC above the dew point of watervapor and most industrial solvents, is intended for application conditionsthat aren’t as severe. These models are all available with the NEMA 4Xoutdoor housing for outdoor installation in any kind of climate. And forrelatively clean applications such as rotogravure and flexographicprinting we offer the SNR671 which is run at 60ºC.

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PrevEx TailoredTo Your Requirements

NEMA 4XOutdoor Housing

NEMA 12/13Indoor Housing