♦Adopt double high-impedance three-electrode system, with online one-key calibration, real-time temperature compensation, electrode loose alarm, electrode good or bad alarm during calibration, and power-off protection (the calibration result and preset data will not be lost due to shut down or power failure). ♦Over-current protection, over voltage protection, high measurement accuracy, fast response, long life and so on. ♦Small in size, light in weight, easy to install and maintain, and the standard industrial signal output (0-5V, 0-10V, 4-20MA, Modbus RTU485) can meet the limit of on-site connection to various real-time monitoring equipment.