Abstract
Our objective was to develop and validate a freely downloadable, open-source, 3D printed rain gauge calibrator that can be adjusted for a wide range of gauges. The calibrator applies constant low, medium, and high-intensity water delivery rate, and allows the user to modify the design to conform to their system based on parametric design. The design may be modified and printed using freely available computer-aided design (CAD) software. Currently available devices for calibration tend to be designed for specific rain gauges, are expensive, employ low-precision water reservoirs, are not field portable, and do not offer the flexibility needed to test the ever more popular small-aperture rain gauges (smaller surface area to catch precipitation than the classical 200mm standard). To overcome the fact that different 3D printers yield different print qualities, we devised a simple post-printing step that controls critical dimensions to assure robust performance. Specifically, orifices of the calibrator are drilled to reach the target flow rates. Laboratory tests showed that flow rates of 25, 50, and 83 ml/min were consistent between prints (coefficient of variation of 3.9, 2.2, and 1.8, % respectively), and between trials of each part, while the total applied water was precisely controlled (0.1%) by the use of a volumetric flask as the reservoir. The entire system costs under US$10.
Highlights
Rain gauges are essential tools for high-quality and reliable observation of precipitation
The small standard deviation and coefficient of variation indicate that the post-processing is eliminating most of the variation is produced by the 3D printer’s inability to reproduce the same piece
There was still variability in the rates even with careful drilling of all of the orifices, but it is significantly reduced compared to the stoppers that are not drilled after printing
Summary
Rain gauges are essential tools for high-quality and reliable observation of precipitation. They are the most direct method for surface rainfall quantification, as utilized for hydrological, climatological, and agricultural studies (Habib et al, 2012). The following question arises concerning the validity of rain gauges: How do we know that the sampler is correctly reporting the rainfall amount. To validate the integrity of the rain gauge requires the application of a known volume of water at a known constant flow rate. It is essential to do dynamic calibration, calibration that requires a constant flow rate, because it allows for compensation of error cause by spillage (Ciach, 2003; Texas Electronics, 2019). Spillage occurs when a tipping bucket is not able to capture the rainfall due to the transition between the tipping, the rain is spilled and
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
