SLIA097 March   2022 DRV5011 , DRV5011 , DRV5012 , DRV5012 , DRV5013 , DRV5013 , DRV5015 , DRV5015 , DRV5021 , DRV5021 , DRV5023 , DRV5023 , DRV5032 , DRV5032 , DRV5033 , DRV5033 , TMAG5110 , TMAG5110 , TMAG5111 , TMAG5111 , TMAG5123 , TMAG5123 , TMAG5231 , TMAG5231 , TMAG5328 , TMAG5328

 

  1.   Trademarks
  2. 1Introduction
  3. 2Flow Meter Design
    1. 2.1 Mechanical Considerations
    2. 2.2 Magnetic Considerations
      1. 2.2.1 Material
      2. 2.2.2 Geometry
      3. 2.2.3 Magnetic Deign Tools
    3. 2.3 Hall-Effect Sensor Considerations
      1. 2.3.1 Device Sensitivity
      2. 2.3.2 Unipolar Switch
      3. 2.3.3 Omnipolar Switch
      4. 2.3.4 1D Latch
      5. 2.3.5 2D Integrated Latch
      6. 2.3.6 Bandwidth
      7. 2.3.7 Package
      8. 2.3.8 Power Consumption
  4. 3Flow Meter Development
    1. 3.1 3D-Print Recommendations
    2. 3.2 Flow Meter Assembly Considerations
    3. 3.3 Flow Meter Assembly Guide
      1. 3.3.1 Shaft Installation
      2. 3.3.2 Bearing Installation
      3. 3.3.3 Magnet Installation
      4. 3.3.4 Impeller Installation
      5. 3.3.5 O-ring Installation
      6. 3.3.6 Flow Meter Top Installation
      7. 3.3.7 PCB Mounting
      8. 3.3.8 Cover Installation
  5. 4Flow Meter Evaluation
    1. 4.1 Flow Meter Testing
  6. 5Error Sources
    1. 5.1 Mechanical Error
    2. 5.2 Sampling Error
    3. 5.3 Magnetic Error
  7. 6Flow Meter PCB
    1. 6.1 PCB Schematic
    2. 6.2 PCB Layout
  8. 7Bill of Materials (BOM)
  9. 8References

2.3.1 Device Sensitivity

Select a Hall-effect sensor to have adequate sensitivity for the magnet used in the flow meter. The positioning and size of the magnet can have significant influence on magnetic flux density sensed by the Hall-effect sensor. Hall-effect devices are often available with multiple sensitivity options to suit the specific sensitivity requirements for the application. It is necessary to select a Hall-effect sensor with enough magnetic headroom to reliably trigger on changes in magnetic field.