Salient Features: ① Automatic sensor cleaning ② One-key reset (restore to factory settings) ③ Simultaneous display of multiple parameters ④ Triple relay control ⑤ Multiple display modes ⑥ Keypress sound feedback ⑦ Water and gas-proof housing Technical Parameters: 1. Measuring range: 0.00–19.99 mg/L 2. Resolution: 0.01 mg/L 3. Slope calibration range: 50–150% 4. Electrode cleaning time: 1s–99m59s 5. Cleaning interval: 1–720 min 6. Temperature compensation range: 0.0–45.0°C (automatic or manual) 7. Relay control range: 0.00–19.99 mg/L 8. Hysteresis adjustment range: 0–3.00 mg/L 9. Current output: Two optically isolated (reversible) 4–20 mA channels 10. Signal output load: ≤500 Ω 11. Power supply: AC 220V ±10% 12. Dimensions: 245 × 180 × 124 mm 13. Weight: 1.1 kg 14. Mounting method: Wall-mounted 15. Operating conditions: ① Ambient temperature: -5–55°C ② Relative humidity: ≤90% ③ No strong magnetic interference except Earth’s magnetic field