Instrument Features Description – Large screen dot-matrix LCD display, Chinese menu operation, simultaneous display of multiple parameters – Menu-driven operation, user-friendly design, simpler to use – Superior anti-interference design suitable for strong interference field operations and electromagnetic interference resistance – Automatic measurement frequency switching: avoids electrode polarization, improves measurement accuracy – Automatically achieves wide-range measurement from ppb to ppm levels – IP65 all-weather waterproof and gasproof, usable in any harsh environment – Two relay contact points, independently selectable for high/low control – Independently adjustable high/low setpoint hysteresis width to prevent relay oscillation around setpoints – Automatic temperature compensation function – Compatible with sensors from other brands – Communication function: RS-485 communication interface convertible to RS-232 – Isolated 4–20mA current output, corresponding pH value can be arbitrarily set – Optional PC online acquisition software for data collection and processing – DO value temperature compensation function – Automatic standard solution recognition, factory reset capability – Watchdog function: ensures the instrument does not freeze – Power-off protection >10 years – Core components from internationally renowned brands Technical Specifications 1. Measurement range: 0–200 μg/L, 0–20 mg/L, automatic range switching. 2. Temperature: -10–130°C 3. Resolution: 0.1 μg/L, 0.01 mg/L, 0.1°C 4. Accuracy: μg/L: ±1.0% FS; mg/L: ±0.5% FS, ±0.3°C 5. Temperature compensation: Automatic (±10°C offset adjustment), Manual (calibration temperature settable) 6. Control interface: Two sets of ON/OFF relay contacts for high and low alarm signals 7. Signal isolation output: Optocoupler isolated 4–20mA signal output 8. RS-485 communication: One RS-485 serial output, supports up to 100 devices, maximum distance 1000m, convertible to RS-232 for direct PC connection. 9. Relay: Hysteresis settable arbitrarily, relay load: 10A; 220VAC 10. Operating conditions: Ambient temperature 0–60°C, relative humidity ≤90% 11. Output load: Load <500Ω (0–10mA), load <750Ω (4–20mA) 12. Operating voltage: 220VAC ±10%, 50/60Hz (or DC24V) 13. Housing material: ABS 14. Dimensions: 98×105×150mm 15. Panel cutout dimensions: 91×91mm 16. Weight: 1.5kg