From a measurement technology viewpoint, the Optiflux range of electro- magnetic flow meters was one of the highlights at this year’s Interkama fair. These flow meters, which have been subjected to close examination and appraisal by industry experts, provide significantly improved metrological characteristics. A single transmitter for the complete range means just one solution for all applications. The star feature however, is the 3 x 100 % diagnostic functionality for optimum performance.
Günter Pinkowski
In the past, diagnostic analysis has usually been restricted to device diagnostics, such as checking the microcontroller or the memory. The Optiflux, on the other hand, incorporates all the process diagnostics specified in VDI/VDE/Namur 2650. This means more information for maintenance engineers – they are kept informed about the device status and the quality of the measured value, and they are given pointers to possible application errors which can then be used for preventive maintenance to help avoid device and system failures.
Optiflux monitors potential problems in the application, such as gas entrainment, electrode corrosion, fouling or short-circuiting. The device can also detect extremely low conductivity, media changes, partial filling, liner deformation, external magnetic fields, changes in the flow profile and very high process temperatures. Limit values can be defined for all these parameters, enabling the Optiflux to be tailored to specific applications. With a little experience, users can anticipate and successfully preclude such problems.
Out-of-spec diagnostics
Out-of-spec diagnostics means the Optiflux can sense, online and cyclically, whether it is still within the specifications. The accuracy of the field current for generating the magnetic field and the device linearity are verified by injecting a test signal. Using one of the communication interfaces (e. g. Hart) and Krohne’s Pactware operating tool, it is possible to view test results and print verification certificates. This avoids time-consuming manual verification measurements. The usual device diagnostic functions are also integrated, in other words microprocessors, software sequences, memory modules, electronic equipment temperatures and outputs are all tested.
Wide range of applications
A recent expertise confirms the metrological characteristics of the Optiflux: ‘‘The most ingenious thing about the Optiflux is its intelligent diagnostics capabilities. They offer a high level of reliability in operation.’’
Modern technology has enabled a significant improvement in the measurement performance of the EMF. The effects are particularly noticeable in areas where today’s flow meters encounter difficulties, for example when measuring media flow with ultra-low conductivity, rapid media changes with a corresponding change in the pH value or media with a high solids content of the kind that occur in the paper industry.
The paper sector, in particular, was one of the last areas of application for AC field EMFs. The results obtained from several applications in which the Optiflux was used in parallel with the AC field EMF confirm that the new device invariably reveals its metrological superiority.
Even the standard device meets the high requirements for accuracy and repeatability. Owing to its extensive diagnostic facilities, is ideal for custody transfer applications and is certified to OIML.
Accurate and universal
Improved measuring equipment and highly effective shielding in the sensor have resulted in an accuracy of 0.15 % and – of even greater interest to users – a repeatability of 0.06 % of the measured value. With only one signal transmitter, Optiflux covers all applications from simple water measurements to corrosive or abrasive media. This simplifies engineering, procurement, training and stock-keeping, leading to significant cost savings.
Thanks to the modular platform concept, four inputs and outputs are available in virtually every combination: Ex or non-Ex; passive or active, galvanically separated – also from each other – and of course Namur-compliant.
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