Environmental Monitoring Equipment & Supplies • Sales, Rental & Service by Enviro-Equipment — Charlotte, North Carolina USA

  • Options to measure pH, Dissolved Oxygen (DO), Conductivity, Salinity, Total Dissolved Solids (TDS), Seaweater Specific Gravity, Temperature, Turbidity, Water Depth, and Oxidation Reduction Potential (ORP).
  • Model with GPS available
  • Optional Flow-Cell available for low-flow sampling
  • View all readings on one screen

The U-50 Series multi-parameter water quality meters are equipped to measure and log data for as many as 11 parameters simultaneously with one single probe. Experience the durability, reliability and intuitive software that will exceed your expectations. Monitor surface water and ground water by deploying the probe directly into a body of water or using a flow cell.

Model Comparison
Parameter U-51 U-52 U-52G U-53 U-53G
Dissolved Oxygen
TDS(Total Dissolved Solid)
Seawater specific gravity
Turbidity (LED)      
Turbidity (Tungsten lamp)      
Water depth    
ORP (Oxidation Reduction Potential)
pH (mV)

EPA method 180.1 turbidity design

For high sensitivity turbidity measurements and wiper system using the Model U-53 and Model U-53G.

Dissolved oxygen polarographic sensor

requires little maintenance and is easy to rebuild

Automatic one point calibration feature

Speeds calibration of pH, DO, conductivity, turbidity and water depth

  • All parameters are displayed on one screen.
  • On screen icons display battery power and GPS, USB and probe connectivity.
  • Backlight display and enlarged font capability.
  • Field replaceable sensors.
  • GPS capability.
  • Store as many as 10000 sets of data.

Measurement at a Drainage Ditch or Wharf

Instantaneously monitor, collect and store data while moving the submersed sensor probe unit

Measurement in Marshes

The control unit's waterproof design allows the user to work without concern of splashing or accidentally dropping the control unit in the water. The backlight display allows the user to take measurements in the dark.

Measuring Ground Water from an intake

With the sensor probe lowered and submersed at an intake, 10,000 data sets can be stored in the control unit and transfered to a PC later.

Measurements in Surface Waters

The long 30 meter cable option allows the user to deploy the sensor probe unit and collect measurement data at various depths. The GPS models facilitate environmental surveys of oceans, lakes and rivers.






Measuring Principle


pH 0 to 14

0.01 pH

±0.05 pH


Glass electrode method

Dissolved Oxygen

0 to 50.0 mg/L

0.01 mg/L

±0.1 mg/L

0 to 20 mg/L: ±0.2 mg/L, 20 to 50 mg/L: ±0.5 mg/L

Polarographic method


0 to 10 S/m (0 to 100 mS/cm)

Range Dependant

±0.05% F.S.

±1% F.S. (Median of two-point calibration)

4 AC electrode method


0 to 70 PPT (permillage)

0.1 PPT

±1 PPT

±3 PPT

Conductivity conversion

Total Dissolved Solids (TDS)

0 to 100 g/L

F.S. 0.1%

±2 g/L

±5 g/L

Conductivity conversion

Seawater Specific Gravity

0 to 50 δt

0.1 δt

±2 δt

±5 δt

Conductivity conversion


-10 to -55°C


±0.10°C (at calibration point)

JIS class B platinum thermometer sensor (±0.3 + 0.005 / 1°C)

Thermistor method

Turbidity (U-52, U-52G Only)

0 to 800 NTU

0.1 NTU

±5% (reading) or ±0.5 NTU whichever is greater

±5% (reading) or ±1 NTU whichever is greater

LED transmitting light source, 30° forward scattering method

Turbidity (U-53, U-53G Only)

0 to 1000 NTU

0.01 NTU

±3% (reading) or ±0.1 NTU whichever is greater

  • 0 to 10 NTU: ±0.5 NTU
  • 10 to 1000 NTU: 3% (reading) or ±1 NTU whichever is greater

Tungsten lamp transmitting source and 90° scattering method

Water Depth (U-52G, U-53, U-53G Only)

0 to 30 m

0.5 m

±1% F.S.

±0.3 m

Pressure method

Oxidation Reduction Potential (ORP)

-2000 mV to +2000 mV

1 mV

±5 mV

±15 mV

Platinum electrode method

GPS (U-52G and U-53G Only)