The CI-3100 Series of Remote Sensor Particle Counters continually counts particles from a fixed position. Designed for continuous monitoring, the CI-3100 RS offers users a choice of standard data interface options including RS-485 Modbus and 4-20 mA outputs. This CI-3100 RS model requires both a vacuum source, and DC power source. Alternatively, our CI-3100 OPT version contains an internal power supply and vacuum pump eliminating the need for an external air source and vacuum tubing making installation a snap!