The YSI MultiLab 4010-1W Water Quality Instrument is a single channel input for measuring pH, ORP, Optical-Based DO/BOD, or conductivity. This one-channel meter provides easy-to-use and easy-to-calibrate menu driven operation, and features a large, easy-to-read display, and Intelligent Digital Sensors (IDS) for wireless or plug-and-play connectivity. The IDS sensors automatically store their unique serial number and calibration data. The sensors maintain their calibration data when moved from instrument to instrument and transmit this information to the new instrument so you don't have to recalibrate. In addition, they also digitally process the measurement signal. The CMC function displays continual monitoring of the sensor's measuring range. The range is represented with a bar and calibration points are shown as vertical lines at the cal point. A moving cursor shows the current measured value and indicates if the measurement is within the calibrated range. The QSC is a system to monitor the condition of the pH electrodes. An initial calibration is performed and, afterwards, the sensor status is monitored and graphically displayed. The QSC is a system to monitor the condition of the pH electrodes. An initial calibration is performed and, afterward, the sensor status is monitored and graphically displayed.