HD-200, Field-Installation Type Dissolved Oxygen Meter, HORIBA

The HD-200 is HORIBA's field-installation type dissolved oxygen meter from the H-1 Series, designed for continuous DO monitoring and aeration control in wastewater treatment plants, industrial wastewater facilities, and production process water systems. It uses a bipolar diaphragm polarography sensor (models 5505/5510) with the DO-1100 probe, and features a low-cost membrane cap replacement system — when servicing is required, only the membrane cap needs to be replaced rather than the entire sensor chip, significantly reducing maintenance costs. The inner liquid uses safe KCl (potassium chloride) solution. Automatic temperature compensation is provided by a Pt 1 kΩ temperature sensor built into the DO-1000 probe. Salinity compensation (0–5%) is available for estuarine and coastal monitoring applications. The instrument shares the same H-1 Series platform as the HP-200 and HO-200, providing two isolated 4–20 mA outputs, three relay contacts, a dedicated cleaning output, RS-485 communication, and IP65-rated aluminium housing for demanding indoor and outdoor installations.

Key Features HD-200

• Low-cost membrane cap replacement system — only the cap is replaced, not the full sensor chip, reducing service costs.
• Safe KCl inner liquid — no hazardous chemicals in the sensor electrolyte.
• DO range 0–20 mg/L (display 0–22 mg/L); saturation 0–200%; temperature 0–50 °C; repeatability and linearity ±0.5% FS.
• Salinity compensation 0.0–5.0% for use in seawater, estuarine, and saline process water environments.
• Two isolated 4–20 mA DC outputs (max. 900 Ω): output 1 for DO, output 2 for temperature (free range −20 to 130 °C).
• Three relay contact outputs (SPDT 1c, 250 V AC / 30 V DC, 3 A): R1/R2 selectable as upper/lower alarm, ON/OFF aeration control, or cleaning output; FAIL alarm.
• Dedicated cleaning output (SPST 1a, 250 V AC 0.5 A): period 0.1–168 h; cleaning time 2–600 s; hold time 2–600 s; internal timer or external trigger.
• RS-485 2-wire isolated communication for SCADA/DCS integration.
• Auto-detection of calibration failure (zero and sensitivity errors); calibration history stored.
• IP65 (IEC60529 / JIS C0920); pole (50 A) or wall mount; aluminium alloy housing; SUS304 fittings and hood; reflective monochrome LCD.
• CE marked: EN61326-1 Class A, EN61010-1, RoHS EN50581; FCC Part 15 Class A.

Applications

The HD-200 is suited to continuous DO monitoring and aeration control in municipal and industrial wastewater treatment plants (aeration tanks), river and environmental water monitoring, aquaculture, and production process water management where accurate dissolved oxygen measurement with low-cost sensor maintenance is required.

Installation and Safety Notes

Mount on a 50 A pole or wall. Power: 100–240 V AC ±10%, 50/60 Hz, 15 VA max. When sensor, transmission, or contact input cables are extended to 30 m or more, the CE marking surge test does not apply — fit appropriate surge absorption elements on all connection lines. An internal arrester (spark-over voltage 400 V) is provided. Operating temperature: −20 to 55 °C; storage: −25 to 65 °C; humidity: 5–90% RH non-condensing.

Technical Specifications