The U-50 Series is HORIBA's field-portable multiparameter water quality checker, consolidating up to 11 sensors into a single probe for simultaneous measurement of pH, ORP, DO, conductivity, salinity, TDS, seawater specific gravity, turbidity, water depth, water temperature, and GPS position. Designed for ease of use in field conditions — rivers, groundwater, wastewater — it features one-touch automatic calibration, Auto-Hold data capture, individual sensor replacement, USB data transfer, and impact-resistant construction with a carrying bag as standard.
The U-50 Series is HORIBA's field-portable multiparameter water quality checker, designed to consolidate a wide range of water quality sensors into a single probe for rapid simultaneous measurement at any field location. Up to 11 parameters are measured and displayed simultaneously in a single test — pH, ORP, dissolved oxygen, electrical conductivity, salinity, TDS, seawater specific gravity, turbidity, GPS position, water depth, and water temperature — eliminating the need to carry multiple instruments to a survey site. The series comprises five models: U-51, U-52, U-52G, U-53, and U-53G, which differ in turbidity sensor type (LED 30° scattering vs. tungsten lamp 90° scattering / EPA 180.1 compliant) and GPS capability. Individual sensors can be replaced independently without replacing the entire probe. One-touch automatic calibration with a single standard solution covers all applicable parameters, and an Auto-Hold function captures and holds stable readings for easy recording. Data is stored in memory (10,000 points) and transferred to a PC via USB. The impact-resistant controller and carrying bag make the U-50 Series well suited to demanding field survey environments.
Key Features U-50 Series
- Simultaneous measurement of up to 11 parameters from a single probe — pH, ORP, DO, conductivity, salinity, TDS, seawater specific gravity, turbidity, GPS (U-52G/U-53G), water depth, water temperature.
- Five models: U-51 (basic, LED turbidity), U-52 (LED turbidity, wiper), U-52G (U-52 + GPS), U-53 (tungsten 90° turbidity, EPA 180.1, wiper), U-53G (U-53 + GPS).
- U-53/U-53G turbidity sensor compliant with EPA Method 180.1 (tungsten lamp, 90° scattering); equipped with wiper.
- Individual sensor replacement — only the faulty or worn sensor is replaced, not the full probe; sensor replacement timing indicated by built-in diagnostic function.
- One-touch automatic calibration using a single standard solution (pH 4) — covers all calibratable parameters simultaneously.
- Auto-Hold function — automatically captures and holds stable measurement values during field readings.
- 10,000-point data memory; USB connectivity for easy PC data transfer.
- Large backlit 320 × 240 LCD; icon-based interface; one-hand operation.
- Probe: max. depth 30 m; JIS IPx8 (with sensor cable connected); cable options 2/10/30 m; liquid contact materials: PPS, glass, SUS316L, SUS304, FKM, PEEK, titanium, FEP, POM.
- Controller: JIS IPx7; impact-resistant soft resin; 4 × C batteries; approx. 70 h battery life (backlight off); carrying bag included as standard.
Applications
The U-50 Series is suited to field water quality surveys in rivers, lakes, reservoirs, groundwater monitoring wells, coastal and seawater monitoring, wastewater discharge points, and environmental impact assessments — wherever rapid simultaneous multiparameter measurement at multiple locations is required without a fixed installation.
Installation and Safety Notes
Designed for field portable use; no fixed installation required. Maximum probe depth 30 m. Operating temperature: −5 to 45 °C (controller); −10 to 55 °C (probe). Storage temperature: −10 to 60 °C. Power: 4 × C alkaline batteries. Flush the probe with clean water after use in turbid or saline samples. Cable must be connected for IPx8 rating. Standard cable 2 m; optional 10 m and 30 m cables available.
Technical Specifications
| Models | U-51; U-52; U-52G; U-53; U-53G |
| Parameters (simultaneous) | pH; ORP; DO; Conductivity; Salinity; TDS; Seawater specific gravity; Turbidity; GPS (U-52G/U-53G); Water depth; Water temperature |
| pH | Glass electrode; 0–14 pH; resolution 0.01 pH; repeatability ±0.05 pH; accuracy ±0.1 pH; 2-point calibration; auto temp. compensation |
| ORP | Platinum electrode; −2000 to +2000 mV; resolution 1 mV; repeatability ±5 mV; accuracy ±15 mV |
| DO | Polarographic; 0–50.0 mg/L; resolution 0.01 mg/L; repeatability ±0.1 mg/L; accuracy 0–20 mg/L ±0.2 mg/L / 20–50 mg/L ±0.5 mg/L; salinity compensation 0–70 PPT (auto); auto temp. compensation |
| Conductivity | 4-electrode AC; 0–100 mS/cm; auto range; repeatability ±0.5% FS; auto temp. conversion (25 °C) |
| Salinity | Conductivity conversion; 0–70 PPT; resolution 0.1 PPT; repeatability ±1 PPT; accuracy ±3 PPT |
| TDS | Conductivity conversion; 0–100 g/L; resolution 0.1% FS; repeatability ±2 g/L; accuracy ±5 g/L; user-defined conversion factor |
| Seawater specific gravity | Conductivity conversion; 0–50 σt; resolution 0.1 σt; repeatability ±2 σt; accuracy ±5 σt; display σt / σ0 / σ15 |
| Turbidity (U-51/U-52/U-52G) | LED 30° scattering; 0–800 NTU; resolution 0.1 NTU (0–99.9) / 1 NTU (100–800); repeatability ±5% or ±0.5 NTU; accuracy ±5% or ±1 NTU |
| Turbidity (U-53/U-53G) | Tungsten lamp 90° scattering (EPA Method 180.1); 0–1000 NTU; resolution 0.01–1 NTU (range dependent); repeatability ±3% or ±0.1 NTU; accuracy 0–10 NTU ±0.5 NTU / 10–1000 NTU ±3% or ±1 NTU; wiper included |
| Water depth | Pressure method; 0–30 m; resolution 0.05 m; repeatability ±1% FS; accuracy ±0.3 m |
| Temperature | Thermistor; −10 to 55 °C; resolution 0.01 °C; repeatability ±0.10 °C; JIS class B Pt sensor |
| GPS | Available on U-52G and U-53G |
| Probe max. depth | 30 m |
| Probe dimensions | Ø96 mm × 340 mm (approx.) |
| Probe weight | Approx. 1,800 g (excl. cable) |
| Cable length | Standard 2 m; optional 10 m / 30 m |
| Probe water resistance | JIS IPx8 (with sensor cable connected) |
| Controller dimensions (W × D × H) | 115 × 66 × 283 mm |
| Controller weight | Approx. 800 g |
| Controller water resistance | JIS IPx7 |
| Display | 320 × 240 LCD with backlight; icon-based interface; one-hand operation |
| Data memory | 10,000 points |
| Communication | USB |
| Power | 4 × C alkaline batteries; approx. 70 h / ~500 measurements (backlight off, >20 °C) |
| Operating temperature (controller) | −5 °C to 45 °C |
| Storage temperature | −10 °C to 60 °C |
| Liquid contact materials | PPS; glass; SUS316L; SUS304; FKM; PEEK; titanium; FEP membrane; POM |
| Standard accessories | Carrying bag; calibration cup; standard accessories |
| Manufacturer | HORIBA Advanced Techno Co., Ltd. |
| Brand | Horiba |
