Salient Features: ① Automatic sensor cleaning ② One-key factory reset ③ Simultaneous multi-parameter display ④ Three sets of relay control ⑤ Self-diagnostic startup ⑥ Online value calibration ⑦ Keypress sound feedback Technical Specifications: 1. Measuring Range: 0.00–10.00 mg/L, 0.0–100.0 mg/L, 0–1000 mg/L, 0–10000 mg/L (four ranges) 2. Resolution: 0.01 mg/L 3. Zero Calibration Range: 50 mV 4. Slope Calibration Range: 20%–180% 5. Temperature Compensation: 0–99.9°C (automatic or manual) 6. Relay Control Range: 0.00–19.99 7. Automatic Cleaning Duration: 1 s–99 m 59 s 8. Cleaning Interval: 1–720 min 9. Signal Output: 4–20 mA (adjustable range) 10. Operating Voltage: AC 220 V ±10%, 50/60 Hz 11. Dimensions: 185 × 155 × 115 mm 12. Mounting: Wall-mounted 13. Operating Conditions: ① Ambient Temperature: –5–55°C ② Relative Humidity: ≤90% ③ No strong magnetic interference except Earth’s magnetic field