Mass Flow Controller System
Client: Brad Hodgeman– Instrumentation Specialist, Comparative Biosciences Advisor: Professor Emeritus John G. Webster Team Members: Aaron Huser, Cole Kreofsky, Dana Nadler, Joe Poblocki
University of Wisconsin - Madison Biomedical Engineering Design Courses INTELLECTUAL PROPERTY STATEMENT
Hodgeman researches hypoxia and hyperoxia with rats at the Veterinary Science Building. Current mass flow controllers are too inaccurate, and the software is outdated. There are undesirable, manual aspects to protocol that need to be eliminated.
The purpose of this project is to design a system that can create a reproducible and accurate hypoxic/hyperoxic environment with the capability of oscillating between various concentrations of oxygen and nitrogen.
Hypoxia and hyperoxia are atmospheric conditions, where the oxygen level deviates below or above normal (21%) concentration, respectively. Hypoxia is a form of respiratory distress which induces certain physiological responses by the neuro-respiratory system. These responses have been associated with SIDS, sleep disorders, spinal cord injury, etc.
Mass Flow Controllers
Mass flow controllers often aid in hypoxia research due to their ability to alter Oxygen concentrations to desirable levels for testable consequences.
Current Gas Control System
controlled Command Module (HyperTerminal Software) Four Analog Mass Flow Controllers Two Manual Mass Flow Controllers Four Chambers
gas concentrations and flow rates through a chamber Software with an easy to use interface and customizable features Accurate mass flow controllers, digital or analog Uniform tubing resistance Low sound level Capability for further expansion
Graphical programming environment made for engineers and scientists Client has had previous experience using DASYLab – a program similar to LabVIEW Ability to customize programs easily and efficiently Variety of open source examples of current programs available
Main Areas of Focus
Mass Flow Controller Manufacturers
Sierra Instruments – Series 100 Smart-Trak™ Advanced Energy – Aera® Mach One Mykrolis – Intelliflow ™ II
DeviceNet RS485 RS232
Company Advanced Energy Mykrolis Sierra Instruments Accuracy +/- 0.5% (4) +/- 0.25% sp plus 0.35% fs (3) +/- 0.7% of reading + 0.3% fs (2) Response Time <= 250 ms (5) 1 sec (3) 2 sec (2) Price $1675.00 US (3) $1880.00 US (2) $1370.00 US (4) Customer Service (3) (3) (4) Flow Range 3 L/min (2) 5 /min (5) 6 L/min (4) Total
17** 16 16
Low=1 - 5=High
**The Numbers Don't Lie!
Digital vs. Analog
Digital Accuracy is a function of set point (sp) Multiple gas calibration curves Multiple set point calibration More cost efficient Analog Accuracy is a function of full scale (fs) Manual individual gas calibrations
Most Expensive Too sophisticated for this system
Least Expensive Ergonomically incompatible
Moderately Expensive Ability to daisy-chain cables
LabVIEW software, RS485 interface and AE MFCs