The Real UV254 M1500 probe from Real Tech is accurate and reliable in open-channel or nonpressurized wastewater UV disinfection. It monitors UV transmittance between 15 and 100 percent. An optional Real Controller wall-mounted operator interface allows convenient control and display. The 4-20 mA output links real-time UVT measurements with the operator or UV reactor to meet treatment goals while saving operator time and money. 877/779-2888; www.realtechwater.com.