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<p>The magnitude and controls of particulate carbon exported from surface waters and its remineralization at depth are poorly constrained. The Carbon Flux Explorer (CFE), a Lagrangian float-deployed imaging sediment trap, has been designed to optically measure the hourly variations of particle flux to kilometer depths for months to seasons while relaying data in near-real time to shore via satellite without attending ships. The main optical proxy for particle load recorded by the CFE, volume attenuance (VA; units of mATN&thinsp;cm<span class="inline-formula">²</span>), while rigorously defined and highly precise, has not been robustly calibrated in terms of particulate organic carbon (POC), nitrogen (PN) and phosphorus (PP). In this study, a novel 3-D-printed particle sampler using cutting edge additive manufacturing was developed and integrated with the CFE. Two such modified floats (CFE-Cals) were deployed a total of 15 times for 18–24&thinsp;h periods to gain calibration imagery and samples at depths near 150&thinsp;m in four contrasting productivity environments during the June 2017 California Current Ecosystem Long-Term Ecological Research (LTER) process study. Regression slopes for VA&thinsp;:&thinsp;POC and VA&thinsp;:&thinsp;PN (units mATN&thinsp;cm<span class="inline-formula">²</span>:&thinsp;mmol; <span class="inline-formula"><i>R</i>²</span>, <span class="inline-formula"><i>n</i></span>, <span class="inline-formula"><i>p</i></span> value in parentheses) were <span class="inline-formula">1.01×10⁴</span> (0.86, 12, &lt;&thinsp;0.001) and <span class="inline-formula">1.01×10⁵</span> (0.86, 15, &lt;&thinsp;0.001), respectively, and were not sensitive to particle size classes or the contrasting environments encountered. PP was not well correlated with VA, reflecting the high lability of P relative to C and N. The volume attenuance flux (VAF) to POC flux calibration is compared to previous estimates.</p>