38


Measurement and Testing Online Fuel Oil Viscometer Installs Anywhere


The ViscoJet VJ1 from viscosity specialist Hydramotion Ltd (UK) is a high-performance stand-alone device offering high resolution and accuracy with excellent repeatability.


Unaffected by vibration, gas breakout or flow conditions, the ViscoJet is mounted directly on the line with no offtake or bypass necessary. The instrument is factory-calibrated to certified viscosity standards traceable to NIST and no on-site recalibration is required. Calibration is unaffected by location, so the instrument can be mounted on any size of pipe or tank without needing any special housing or extra pipework. The ViscoJet is a true “fit and forget” device shipped ready for immediate use, enabling continuous viscosity measurement to start within seconds of power-up. The instrument can be connected directly to a PID controller for real- time viscosity monitoring and control.


The ViscoJet is ideal for controlling the preheating of fuel oil to ensure that it has the correct viscosity at the burner, optimising burner performance, minimising pollution, improving efficiency and reducing maintenance costs.


The standard ViscoJet measures viscosities up to 10,000 cP at temperatures up to 200°C (390°F) and pressures up to 70 bar (1015 psi), although extended temperature and pressure range instruments are also available. An integral thermom- eter provides simultaneous measurement of oil temperature, allowing the instant calculation of viscosity corrected to a reference temperature.


The orientation-independent sensor has a solid construction with no moving parts, seals or bearings, so routine maintenance is not required. All instrument-specific data is stored on the sensor, giving complete flexibility of installation as well as facilitating adjustment and performance optimisation. The device is shipped ready for immediate use, enabling viscosity measurement to begin immediately following electrical hook-up.


If the ViscoJet is to replace older equipment, a retrofit adapter can be supplied, eliminating the need to modify existing plant.


Operating on any supply voltage between 12 and 24 volts DC, the ViscoJet provides a 4-20mA analogue viscosity signal and a more comprehensive RS485 serial data link. The associated PC-based ViscoLink software (supplied with the instrument) displays all measured and calculated variables, including live viscosity, current temperature and temperature-corrected viscosity. There is also the facility to export data to Microsoft®


Excel™ for logging and analysis.


Configuring the system for optimum performance is quick and easy using ViscoLink. Installed in minutes, the ViscoJet offers an immediate, reliable and durable solution to the challenges of real-time on-line viscosity measurement in the harshest conditions.


Reader Reply Card No Raising the Standard of Temperature Measurement


Precision thermometry manufacturer ASL (UK) has upgraded its market leading range of AC bridges with the launch of the F252 as a successor to the highly popular F250.


ASL has been producing the industry’s leading high precision


thermometers and temperature bridges for over 40 years. Its equipment is used for primary and secondary calibration verification, process monitoring, sterilisation and validation work by some of the world's most demanding end users including NASA, Boeing, Shell, Esso and all International Standards Laboratories including the National Physical Laboratory.


The ASL F250 Precision Thermometer has been a leading reference temperature standard worldwide for a number of years. Thanks to further advances in technology, ASL has now replaced it with the F252, which is the fastest commercial AC Bridge of this precision class and faster than any DC bridge of similar specification.


It boasts accuracy to within +/-0.01ºC (full range) and resolution of 0.001ºC


(0.0001Ω) with a resistance range of between 0 - 400Ω. It is also the first AC Bridge to be launched with ‘smart probe’ capability.


The F252 also comes with two channels as standard, but four and six channel variations are available with each channel able to work with up to 72 user-defined probes so providing spot on calibration. The F252 also offers single, differential and alternative measurement modes.


The establishment of the RoHS Directive (Restriction of Hazardous Substances) across Europe in 2006 prompted a review of


all thermometry devices. The tight restrictions placed on lead, mercury and cadmium have meant that all thermometer manufacturers have had to adapt some of their approaches.


“This actually presented us with a real opportunity,” says ASL technical manager Peter Andrews. “We are continually reviewing our product offering, but the emergence of the RoHS proposals back in 2003 prompted us to take a new direction.


“The outcome is a much more environmentally sustainable range of products, which create fewer waste disposal problems, and, at the same time, deliver a new standard in precision thermometry with better features than ever. It also provides the user with improved reliability and longer life than its predecessors because it uses solid state switching and has no mechanical components.”


The F252 is capable of measuring temperature ranges to meet ITS90, CVD, EN60751 & IEC751 standards and results are delivered via a LCD backlit display with large numeric, statistical or graphical information. It also comes with USB interface as standard, but optional RS232, IEEE or LAN interfaces are also available.


Reader Reply Card No 124 123


Chevron Updates Older Viscosity Systems for Better Lube Oil Product Reliability


To better measure the viscosity of its high-value lube oils, Chevron Energy Technology Company needed to update to a more modern and reliable viscometer. The company was using viscometers that consisted of tubing and heaters in a bath. In searching for a replacement, however, they did not want to lose the ability to measure viscosity at set temperature.


Chevron turned to Cambridge Viscosity (USA) for a solution. “We selected Cambridge Viscosity because of their advanced piston technology and the fact that the company has a proven track record, with 25 years of experience and thousands of viscometers in operation worldwide,” says John Dempster, Chevron Energy Technology Company.


Cambridge Viscosity retrofitted Chevron’s existing capillary type system with their VISCOpro sensor and electronics under the invitation of Mark Lee of Chevron’s Richmond refinery. The pumps and tubing from the bath system were removed, retaining only the bath fluid with its heating/cooling capability. Cambridge Viscosity installed its sensor, fitted to the existing bath unit with a sealed bracket. The sensor was immersed directly into the bath fluid and very accurate temperature control was achieved.


John Dempster says the company’s primary goals were to achieve a higher degree of reliability and reduce the need for cleaning and maintenance required by the old system. The previous system relied on the measurement of viscosity and refractive index to correlate the Viscosity Index. This is an inaccurate method, compounded by the necessity to regularly clean the refractometer. Using Cambridge Viscosity’s technology, proven on a single viscosity measurement, Chevron will be able to measure viscosity at two temperatures to directly determine the Viscosity Index of the lube oil using ASTM methodology.


“We are very pleased with the accuracy and reliability of the retrofit,” says John Dempster. “We plan to retrofit additional systems in the coming months and use this technology for other upcoming projects.”


Cambridge Viscosity’s patented sensor technology complies with ASTM D7483-08 and directly correlates to ASTM D445. The sensor has only one moving part, a piston, driven electromagnetically through fluid in a small measurement chamber. A deflector, positioned over the piston, moves fluid into the measurement chamber, while two coils move the piston back and forth at a constant force. Proprietary circuitry analyzes its two-way travel time to measure absolute viscosity. Because all wetted parts are stainless steel and the piston is in constant motion, the sampling area is continually scrubbed clean. There is no need for frequent calibration and very little maintenance is required.


In addition to the sensor itself, each viscometer includes a built-in temperature detector that senses the actual temperature in the measurement chamber in order to determine a temperature-compensated viscosity (TCV) reading. This increases accuracy under the changing environmental conditions in which the viscometer operates.


With measurement capabilities ranging from 0.2 to 20,000 cp – or higher with Camb- ridge’s custom engineering capability – each Cambridge Viscosity viscometer has been designed to deliver the precision and flexibility needed in the lab or refinery.


Reader Reply Card No 125


February/March 2010


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52