Comparison of Three Commercial Automatic Boom Height Systems for Agricultural Sprayers

Automatic boom height systems reduce the variability of agricultural sprayer boom height. Consistent boom height is important for three key reasons: to reduce uneven spray dispersion if the boom is too low, to reduce spray droplet drift if the boom is too high, and to reduce damage to the boom or crop if the boom is too low. No data is available comparing commercial boom height systems. Three leading North American automatic boom height systems were compared: John Deere BoomTrac Pro (System A), Raven AutoBoom® XRT (System B), and Norac UC5TM Passive Roll (System C) on a John Deere R4045 (Systems A and B) and RoGator 1100C (Systems B and C). Each system was evaluated with three test runs for at least three speeds over each of a mild, medium, and rough terrain course. Boom heights at the left and right outside sensors were measured with the AutoBoom XRT sensors. The accuracy of the automatic boom height systems was quantified with root mean squared deviation (RMSD), the Herbst-modified Hockley Index, and the fraction of points within 10 and 25 cm of target (f10 and f\u3c25). With four exceptions out of 216 comparisons, System B significantly outperformed System A on the R4045 and System C on the RoGator for each metric, at each sensor location, at each speed, on each terrain. At 26 km/h on medium terrain, the RMSD for Systems A and C was 174% and 107% larger than System B, respectively. At 26 km/h on medium terrain, the fraction of points within 25 cm (f\u3c25) was 56% and 21% higher for System B than Systems A and C, respectively. These results indicate System B kept the boom significantly closer to target with significantly less height variability

Initial Component Testing for a Germanium Array Cryostat

This report describes progress on the construction of two ultra-low-background cryostats that are part of the NA-22 funded “Radionuclide Laboratories” (RN Labs) project. Each cryostat will house seven high-purity germanium crystals (HPGe). These cryostats are being built from a limited set of materials that are known to have very low levels of radioactive impurities. The RN Labs instrument is designed to take advantage of low background performance, high detection efficiency, and - coincidence signatures to provide unprecedented gamma spectroscopy sensitivity. The project is focused on improving gamma analysis capabilities for nuclear detonation detection (NDD) applications. The instrument also has the potential for basic nuclear physics research. Section 1 provides the background for the project. Section 2 discusses germanium crystal acceptance testing. Design problems were found after the first delivery of new detectors from the vendor, Canberra Semiconductors. The first four crystals were returned for repair, resulting in a delay in crystal procurement. Section 3 provides an update on copper electroforming. In general, electroforming parts for RN Labs has proceeded smoothly, but there have been recent problems in electroforming three large copper parts necessary for the project. Section 4 describes the first round of testing for the instrument: anti-cosmic scintillator testing, electronics testing, and initial vacuum testing. Section 5 concludes with an overall description of the state of the project and challenges that remain