Estimating ram sperm concentration using an ESP32-based absorbance device: Design, calibration, and field applicationI Dewa Gede Wicaksana Prabaswara, Putu Oki Wiradita Aryawan, Surya Kusuma Wijaya and Mokhamad Fakhrul UlumBIO Web Conf., 186 (2025) 03011DOI: https://doi.org/10.1051/bioconf/202518603011