Bubble Detection Sensors for Non-conducting Liquids

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• Bubble Detection Sensors for Non-conducting
  Liquids

Craig E. Nelson - Consultant Engineer
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• Goals for Bubble Sensing Devices
• Detect small bubbles in a small fluid channel
  without immersion of sensor parts in the channel
• Differentiate between a gas filled channel and a
  fluid filled channel
• Be sensitive to rather small gas fractions
  passing down the small fluid channel

• Desirable Features
• Small and flat
• Inexpensive
• Reliable

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Zen No Sensor Sensor EIS Magnetostatic
Methods Magnetostatic Bubble Sensing
Impedance Method 1 Coil Magnetostatic Bubble
Sensing Transformer Method 2
Coils Magnetostatic Bubble Sensing Gradiometer
Method 3 Coils Galvanic Contact
Methods Noble Metal Electrodic
Methods Permittivity ( Capacitive )
Methods Absolute Capacitance Differential
Capacitance Mass flow Methods Mechanical
Resonance of Fluid Loaded Beams Ultrasonic
Methods Pitch Catch Mechanical Impedance
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Nature of the Bubbles
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Nature of the Bubbles
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Nature of the Bubbles
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Nature of the Bubbles
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Nature of the Bubbles
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Electrical Impedance Bubble Sensing
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Electrodic Bubble Sensing Methods - MEMS
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Zen No Sensor Sensor - EIS
Measure the liquid electrical impedance using
electrode already in place for other reasons.
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Capacitive Bubble Sensing Methods
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Mass Resonance Bubble Sensing - MEMS
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Optical Bubble Sensing Methods
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Optical Bubble Sensing Schemes
Pitch Bounce - Catch
Pitch - Catch
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Optical Bubble Sensing Pitch Catch Method
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Optical Bubble Sensing TIR Method
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Optical Bubble Sensing Pitch Catch Method
Flow In
Flow Out
Photo detector
LED
This bubble detection method cannot discriminate
between all gas and all electrolyte
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Optical Bubble Sensing Pitch Catch Method
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Optical Bubble Sensing Total Internal
Reflectance ( TIR ) Method
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Optical Bubble Sensing Pitch Bounce Catch Method
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Optical Bubble Sensing TIR Method
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Effect of Target Distance and Orientation
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Optical Bubble Sensing Pitch Bounce Catch Method
Fiber optic path extension
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Optical Sensing Total Int. Reflection Method
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Optical Bubble Sensing Other Geometries
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Optical Bubble Sensing Other Geometries
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Optical Bubble Sensing Other Geometries
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Optical Bubble Sensing Other Geometries
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Electronics Optical Sensing
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Optical Bubble Sensor Electronics - Basic
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Optical Bubble Sensor Electronics - Practical
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Optical Bubble Sensor Electronics - Practical
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Optical Bubble Sensor Electronics - Practical
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Optical Bubble Edge Detector
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Other Bubble Sensing Schemes
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Capacitive Bubble Sensing Methods
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Mass Resonance Bubble Sensing - MEMS
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Doppler Ultrasonic Bubble Sensing
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Ultrasonic Bubble Sensing System Diagram
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Doppler Bubble Sensing Signal Patterns
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Typical Ultrasonic Bubble Sensing Setup
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Bubble Sensing in Small Tubing - Cosense
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Ultrasonic Bubble Sensing - Resonance
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Commercial Off the Shelf ( COTS ) Product
Offerings
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Optical Sensing Commercial Device - Hohner
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Ultrasonic Bubble Sensing - Introtek
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Ultrasonic Bubble Sensing - Zevex
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Optical Bubble Sensing Erlich Industrial Dev.
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Optical Bubble Sensing Optek
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Optical Bubble Sensing Optek
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Optical Bubble Sensing TIR Method
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Optical Bubble Sensing TIR Method
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Optical Bubble Sensing TIR Method
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Optical Bubble Sensing TIR Method
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Optical Bubble Sensing TIR Method
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Summary and Conclusions
A wide variety of bubble detection schemes
suitable for use with non-conductive liquids have
been introduced Many of these are practical for
miniature application Microprocessor based
electronic readouts for these sensing schemes are
not complex or expensive