Embedded Control System for a High Precision Flow Meter
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
This degree project has been conducted to study flow meters and develop firmware for EC Instrument’s Reciflow. Flow rate is the volume of a fluid or mass of a substance which passes through a surface per time unit. Conversion can be made between volumetric and mass flow rate if the gas density is known. A market survey showed that Coriolis and thermal mass flow meters and positive displacement (volumetric) flow meters, as the Reciflow, are the most common kinds. The Reciflow consist of a system-on-board and a displacement meter with an optical encoder. The displacement meter is a cylinder with a piston within and valves at the ends. The firmware controls the valves so that the piston can reciprocate.
The components of the Reciflow affects the accuracy and it is estimated to ±0;025 % for non-normalized and ±0;2 %for normalized flow. It is measured under normal conditions to be ±0;2 %normalized, relative to a reference. Further experiments must be performed to verify the accuracy and also the precision. The actual measurement of flow rate and volume is made with the encoder: as a difference in time between signal edges and the total number of edges accounted for. Data with random noise is filtered with moving average filters and heuristic methods is used to handle static noise. Serial communication has been implemented for on- and off-board uses. A user can interact with the instrument using either a touchscreen or a terminal.
Place, publisher, year, edition, pages
2011. , 82 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-49840OAI: oai:DiVA.org:kth-49840DiVA: diva2:460435
Subject / course
Electronic- and Computer Systems
Master of Science in Engineering - Microelectronics
Smith, Mark, Professor