Features: Wide Voltage Input: 3.3~5.5V Good Compatibility Output: 0~2.3V analogue signal output, compatible with 5V or 3.3V controller AC Excitation Source: effectively prevent probe from polarization Waterproof Probe Easy to Use: for  Arduino compatible, simple connection, plug and play without soldering Specifications:  Signal Transmitter Board Input Voltage: 3.3 ~ 5.5V Output Voltage: 0 ~ 2.3V Working Current: 3 ~ 6mA TDS Measurement Range: 0 ~ 1000ppm TDS Measurement Accuracy: ± 10% F.S. (25 ?) Module Size: 42 * 32mm Module Interface: PH2.0-3P Electrode Interface: XH2.54-2P Description This is an for Arduino-compatible TDS sensor/Meter Kit for measuring TDS value of the water, to reflect the cleanliness of the water. It can be applied to domestic water, hydroponic and other fields of water quality testing. You may also check Liquid Sensor Selection Guide to get better familar with our liquid sensor series. TDS (Total Dissolved Solids) indicates that how many milligrams of soluble solids dissolved in one litre of water. In general, the higher the TDS value, the more soluble solids dissolved in water, and the less clean the water is. Therefore, the TDS value can be used as one of the references for reflecting the cleanliness of water TDS pen is a widely used equipment to measure TDS value. The price is affordable, and it is easy to use, but it is not able to transmit data to the control system for online monitoring to do some water quality analysis. The professional instrument has high accuracy and can send data to the control system, but the price is expensive for the ordinary people. To this end, we have launched an analogue TDS sensor kit which is compatible with for Ar