Online TDS Meter TDS-139M is made of high-quality ABS material, and the surface layer is coated with the anti-static layer. The anti-static ability is higher than that of an ordinary TDS controller, and it is durable and durable. The live digital display shows the TDS value and the backlit display makes the observations clearer. SMT placement technology; ergonomic design with adapters and boxes for easier carrying. It can be continuously measured for 24 hours to avoid reading errors caused by low battery. Equipped with a BNC composite electrode for easy electrode replacement.