The Surveyor RI Plus detector is a member of the Surveyor Plus family of LC devices and is characterized as a fully featured, low-maintenance refractive index detector. This benchtop unit integrates into the Surveyor Plus LC system and can be controlled via an Ethernet connection to the ChromQuest data system computer. Features of the Surveyor RI Plus detector include automatic intensity adjustment that compensates for loss of sensitivity due to flow cell contamination or reduced light levels, a low-volume (8 µL) flow cell to reduce band broadening and a solenoid valve that operates at half the rated voltage and a tungsten lamp, which runs under reduced voltage to increase the life of the components. LEDs provide information about power and communication status as well as operation and temperature. The dynamic measuring range is 1.00 to 1.75 RIU, which makes the detector suitable for a wide range of applications. The ChromQuest data system can be used to implement fully integrated device controls such as automatic temperature control, a rise time filter, a flush function, self-zeroing and built-in calibration procedures. The technical specifications of the Surveyor RI Plus detector include the following detection method: deflection with a refractive index range of 1.00 to 1.75 RIU, an attenuation range of 0.25 to 512 µRIU, a linearity range of 600 µRIU and a noise of ? 2.5 × 10^-9 RIU. The rise time is 0.1 to 3.6 seconds and the polarity can be adjusted positive or negative. Additional features include automatic zero point adjustment, a zero point resolution of ± 10 × 10^-9 RIU, an adjustable offset range from 0 to 500 mV and an offset resolution of 10 mV. The detector also has an integrator output from 0 to 1V/FS and a recorder output from 0 to 10 mV/FS. The external communication options include Ethernet, signal inputs and outputs as well as temperature control from 30 to 50 °C in 1 °C steps or deactivated. The cell volume is 8 µL with a maximum flow rate of 10 mL/min and a pressure rating of 517 kPa. The materials that come into contact with liquids are 316 stainless steel, Teflon and quartz glass. Power supply requires AC100/115/220/240 VAC ± 10%, at 50/60 Hz and a maximum power consumption of 60 VA. The dimensions of the device are 36 cm wide, 47 cm deep and 18 cm high with a weight of 17.3 kg. Labprocure is responsible for this device.