A system called the OBS-5+, with multiple detectors and an embedded controller, was recently developed to extend the measurement range of OBS sensors by a factor of about ten. One limitation of our single-detector systems like the OBS-3 and OBS-4 is that they cannot measure SSC levels greater than about 5,000 mg l^-1 (mud) and 50,000 mg l^-1 (sand). The OBS-5+ (U.S. Patent Number 5,796,481) projects a beam of NIR laser light into a water sample next to two photodetectors. Suspended particles scatter light from the beam onto the detectors and a microcontroller determines suspended sediment concentration (SSC) from their photocurrents. The detector responses to particle concentration are shown on the chart. Because the detectors are unequally spaced from the laser, the particle concentrations corresponding to the peak response are also unequal and after being calibrated with sediment, an OBS-5+ can measure and uniquely resolve sediment SSC values greater than the peaks in response. These systems has been used extensively to monitor dredging and mining operations in the US, EU, China, Vietnam, and Indonesia.