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July 17, 2002 Issue 1 of 5 Pepperl+Fuchs launched its extensive new line of level control instruments in June 2002. To introduce you to the products and their functions, we'll be publishing 5 special issues of "Level Control." This newsletter will cover different facets of our level control products in-depth. Future issues will provide information on selling tools, customer applications, a product selection guide and more. Our first issue is dedicated to frequently asked questions about level control, and is designed to give you a good base of understanding for level measurement technologies. As always, all available software, data sheets, and manuals are on our website. You will find Level Control products listed here.
Frequently Asked Questions about Level Control 1. What types of level products does Pepperl+Fuchs carry? We offer a full range of level products for both point and continuous measurement. For point level control we carry float, magnetic immersion, conductivity, frequency shift/vibration and capacitive probes for both liquid and solid applications. For continuous level measurements, we offer magnetic immersion, pressure, ultrasonic and guided radar solutions for a wide range of applications. Point: Frequency Shift/Vibration 2. Can the frequency shift/vibration technology be used in powder/bulk applications? In some cases it can. P+F uses a two-tined fork for our Vibracon point level sensor. This technology is extremely reliable and suitable for a wide range of liquid applications; however, it can also be used in some solid applications. The key is the density of the material (a hole can be formed in a highly dense material like flour) and the size of the pellets/granules (material can become wedged between the tines). Contact P+F to determine whether your application is suitable for this level technology. 3. Can Vibracon be used in hazardous applications? Yes. Our LVL-M series of frequency shift/vibration sensors can be specified in explosion-proof, intrinsically safe or dust ignition proof versions. We have a full range of North American and European certifications for use throughout the world. 4. What is the smallest process connection available for your Vibracon product? We have several ranges of Vibracon products each with a different application focus – universal, extended length, food grade, corrosion resistant and OEM versions to name a few. Our LVL-A1 is the smallest version and has a ½”NPT process connection while our LVL-M1 goes as small as ¾”NPT and our LVL-T1 is 1”NPT. 5. Can I connect the LVL-A1 in a hazardous location? No. The Vibracon Mini (LVL-A1) is not suitable for mounting in a hazardous location. We have a general purpose certification from CSA as well as and a special overspill certification. 6. What is the output contact rating for your Vibracon product? The LVL-M series of products is available in a universal input power version (19-55Vdc; 19-253Vac) with DPDT relay outputs. The contacts are rated 250Vac, 6A; 1500VA, cosq=1; 750VA, cosq=0.7; 30Vdc, 6A; 125Vdc, 0.2A. 7. Is any configuration necessary for the Vibracon products? No. Vibracon uses the frequency shift/vibration technology to detect the presence or absence of material. This technology is extremely reliable and has long term stability. Plus, it requires no configuration. The only connections required are input power and electrical output. On our LVL-M Series of Vibracons, a switch is present on the electronic module for material density selection but that is only used to change the sensitivity of the electronics. 8. Can the LVL-M1 be used in applications involving process medium temperatures of 150°C? Yes. The LVL-M1 is rated to measure liquid levels at 150°C; however, the ambient temperature must be reduced from 70°C to 50°C with the standard M1 product. If your application requires 70°C ambient temperature AND 150°C process temperature, you must specify the optional temperature separator. This option moves the electronic module away from the process connection thus keeping the electronic module within its operating temperature range. 9. What types of electrical ratings are available on the Vibracon products? Starting with our universal Vibracon M series, it is available in 2-wire AC, 3-wire DC, universal AC/DC with relay output, 8/16mA for intrinsic safety and NAMUR for intrinsic safety. The Vibracon T1/S1/A1 are available in 2-wire AC and 3-wire DC while the A1 is additionally available with an AS-i output. Point: Capacitive 10. Is your capacitive probe suitable for continuous or point level applications? Our LCL line of products is a point level product. It comes in a several voltage ranges and hazardous location certification types. We also employ a unique compensation network that ignores material build-up on the probe by using both a sensor and guard electrode in the probe head to differentiate between a valid level signal or a material build-up condition. 11. What is the minimum dielectric that can be sensed with your capacitive probes? The minimum dielectric for our compact version (LCL1) is 1.6 while our extended length version (LCL2) can measure dielectrics as low as 1.5. Continuous: Pressure 12. Can your Barcon transmitter be used for a bulk solids application? No. The Barcon pressure transmitter is intended to be used for continuous liquid applications. The pressure applied to the transducer is constant with liquids thus accurate results can be achieved. Continuous: Ultrasonic 13. Do you have a non-contact point level sensor? Presently, the best way to solve this application would be to use one of our continuous ultrasonic level transmitters (standard or intrinsically safe version) in combination with a P+F interface unit that provides the user with two programmable relay outputs. This type of configuration highlights the unique capabilities of P+F, a supplier with a wide range of level sensing instruments and the industry's leading supplier of interfaces for standard and intrinsically safe applications. 14. Can Ultrasonic sensors be used for bulk powder applications? Yes. Ultrasonic probes are suitable for both liquid and bulk solid applications; however, there are certain conditions that could limit their usefulness such as suspended dust. The measurement technique uses sound waves to calculate distance so anything that affects the speed of sound could effect the measurement. Generally, ultrasonic transmitters can be used in a wide range of applications for non-contact continuous level measurement. 15. What type of settings can be changed on your ultrasonic transmitter? Our ultrasonic transmitter can be supplied in a standard push-button configuration or in an LCD version. The standard version is preconfigured at the factory to the most universal settings while the LCD version has numerous configuration options. The LC display allow the installer to select the application type, damping value, linearization table (11 values), filtering, simulation and output alarm value to list a few. Overall, the display option gives the customer a great tool to help configure the transmitter to operate at its optimum performance in a given application. Continuous: Guided Radar 16. Can guided radar be used in water applications? Yes. Our Pulscon transmitter uses guided radar technology. This measurement technology is suitable for either liquid or solid level detection. By injecting a pulse onto a stainless steel rod or rope, the total run time of the pulse is measured and a resulting level is calculated. As long as the dielectric rating of the measured media is >1.4, a level can be detected by the electronics. 17. When would you use a coax probe for Pulscon? The coax version probe consists of a rod centered inside a stainless steel tube. By using this type of technology, the injected pulse is more focused on the rod. This focused energy results in the ability to detect low dielectric media (1.4) plus it also eliminates the upper blocking zone. Therefore, you would use the coax for detection of low dielectric material or in applications with small detection ranges. Approvals 18. Do you have any products with 3-A approvals? Yes. For point level applications, our Vibracon (vibration) LVL-M1H and LVL-M2H products are available in sanitary grade finishes and process connections while the Barcon (pressure) LHC-M20 range can be used for continuous level applications involving food and pharmaceuticals. Both of these products are available with 3-A rating.
Next Issue: July 31st
© Pepperl+Fuchs, Inc. 1600
Enterprise Parkway, Twinsburg, Ohio 44087
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