1 / 51

Tipping Bucket Rain Gauge (TBRG) Operation and Calibration

Tipping Bucket Rain Gauge (TBRG) Operation and Calibration. Hydrography Basics Course No. 27743. What is a TBRG?. Rim – of known diameter (usually 200mm or 203mm) which catches precipitation. Funnel – which channels precipitation into the measuring chamber.

tatyana-gaines
Télécharger la présentation

Tipping Bucket Rain Gauge (TBRG) Operation and Calibration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Tipping Bucket Rain Gauge (TBRG) Operation and Calibration Hydrography Basics Course No. 27743

  2. What is a TBRG? Rim – of known diameter (usually 200mm or 203mm) which catches precipitation Funnel– which channels precipitation into the measuring chamber Syphon– controls flow of water into bucket assembly Bucket Assembly– each bucket tip sends voltage free switch closure by means of a reed switch

  3. Syphon V Non-syphon? • Syphon allows a TBRG to deliver consistent results during low AND high rainfall intensities. • Syphon allows the TBRG to be accurately calibrated over a wide range of intensities • Non-syphoning models are calibrated accurately at ONE rainfall intensity only (e.g. 50mm/hr)

  4. Calibration Procedure For Tipping Bucket Rain Gauges

  5. Buretting ‘Buretting’ ensures: • Buckets tip at correct ‘practical’ reading • Buckets tip ‘evenly’

  6. Bucket Capacity • The theoretical value is the volume of water in the bucket that will cause it to tip • e.g. A 200mm catch with a 0.2mm bucket will theoretically tip at 6.28mL

  7. 200mm 0.2mm Bucket Capacity Calculation For 200mm diam. Catchment with 0.2mm bucket Theoretical Value Volume = π × r² × h = π ×10 cm² × 0.02 cm = 6.28 cm³ = 6.28 mL

  8. Bucket capacity • The practical value is less than the theoretical to compensate for the extra water that enters the bucket during the tipping cycle ‘Practical Value’ applies to ‘Syphoning’ Rain Gauges only!!

  9. Calibration Set Up Nozzle Catch Height Syphon

  10. TB3 Standard Calibration Data (200mm diam. catchment) * Based on BOM Specification (20mm equivalent rainfall)

  11. Bucket begins to tip @ 6.28mL bucket holds 6.28 + ?? mL Bucket Tip SequenceSet at ‘Theoretical Value’ ~350ms after tip began…

  12. Bucket begins to tip @ 5.2mL bucket holds 6.28mL Bucket Tip SequenceSet at ‘Practical Value’ ~350ms after tip began…

  13. Syphon/No Syphon compared at each rate 25, 50, 100, 200, 300, 500mm/hr

  14. With Syphon Without Syphon 25mm/hr @ 2x

  15. With Syphon Without Syphon 50mm/hr

  16. With Syphon Without Syphon 100mm/hr

  17. With Syphon Without Syphon 200mm/hr

  18. With Syphon Without Syphon 300mm/hr

  19. With Syphon Without Syphon 500mm/hr

  20. Without a Syphon Video will play 3 times then images enhanced

  21. 100mm/hr 300mm/hr Without Syphon

  22. 100mm/hr 300mm/hr Without Syphon 01/13

  23. 100mm/hr 300mm/hr Without Syphon 02/13

  24. 100mm/hr 300mm/hr Without Syphon 03/13

  25. 100mm/hr 300mm/hr Without Syphon 04/13

  26. 100mm/hr 300mm/hr Without Syphon 05/13

  27. 100mm/hr 300mm/hr Without Syphon 06/13

  28. 100mm/hr 300mm/hr Without Syphon 07/13

  29. 100mm/hr 300mm/hr Without Syphon 08/13

  30. 100mm/hr 300mm/hr Without Syphon 09/13

  31. 100mm/hr 300mm/hr Without Syphon 10/13

  32. 100mm/hr 300mm/hr Without Syphon 11/13

  33. 100mm/hr 300mm/hr Without Syphon 12/13

  34. 100mm/hr 300mm/hr Without Syphon 13/13

  35. With a Syphon Video will play 3 times then images enhanced

  36. 100mm/hr 300mm/hr With Syphon

  37. 100mm/hr 300mm/hr With Syphon 01/12

  38. 100mm/hr 300mm/hr With Syphon 02/12

  39. 100mm/hr 300mm/hr With Syphon 03/12

  40. 100mm/hr 300mm/hr With Syphon 04/12

  41. 100mm/hr 300mm/hr With Syphon 05/12

  42. 100mm/hr 300mm/hr With Syphon 06/12

  43. 100mm/hr 300mm/hr With Syphon 07/12

  44. 100mm/hr 300mm/hr With Syphon 08/12

  45. 100mm/hr 300mm/hr With Syphon 09/12

  46. 100mm/hr 300mm/hr With Syphon 10/12

  47. 100mm/hr 300mm/hr With Syphon 11/12

  48. 100mm/hr 300mm/hr With Syphon 12/12

  49. Summary All ‘syphoning’ type gauges have a distinct ‘signature’, exhibited by ‘variations’ in duration of each bucket tip cycle. Primary cause: - residual water in each bucket prior to syphon discharge - variations in the flow rate of water entering the gauge catchment ‘Signature’ is less noticeable with increasing intensities

  50. HS TBRG Specifications

More Related