This ePAR sensor, is an advanced upgrade to Apogee's ePFD sensor, designed to measure the newly defined ePAR radiation range of 400-750 nm, which research indicates is photosynthetically active, extending beyond the conventional 400-700 nm range. The SQ-617 ePAR is a digital sensor utilizing the SDI-12 communication protocol. It features a durable aluminum housing that is fully submersible and built to endure harsh conditions, along with a high-quality cable. The sensor cable also includes an IP68 marine-grade stainless-steel connector for simplified removal and replacement during maintenance and calibration of permanent installations. Typical applications for ePAR sensors involve measuring total ePAR intensity above plant canopies in various growing environments, monitoring and optimizing grow lights, and conducting research on plant morphogenic activity and photobiology. Many next-generation LED fixtures, sunlight, and other light sources emit these newly validated far-red photosynthetic wavelengths, which have not been measurable by traditional 400-700 nm PAR meters until now.