Process Analysis Systems & Total Solutions for Continuous Water & Wastewater Analysis

Online Dissolved Oxygen

5740 sc Galvanic Membrane Dissolved Oxygen Sensor

Product #: 5740D0B


5740 sc Galvanic DO Sensor: Each sensor includes a replaceable cartridge (with factory-installed, semi-permeable membrane), protector, 12 disposable calibration bags for highly accurate Saturation Method air calibration and integral 10 m (32.8 ft) cable. Full-featured plug-and-play with sc200 or sc1000 Digital Controllers. 


Replaceable Membrane Cartridge

Hach’s 5740 sc Galvanic Dissolved Oxygen (DO) sensors feature a replaceable cartridge, simplifying the delicate and time-consuming task of installing a new membrane. Each cartridge assembly includes a pre-installed, semi-permeable membrane, electrolyte, and electrodes.

Automatic Self-cleaning Accessories

Self-contained air blast cleaning systems, complete with air compressor, are offered to automatically clean the sensor membrane. A separate washer head air blast assembly is also available.

Galvanic Technology

The Hach 5740 sc DO sensor uses a unique galvanic measurement technique. When its lead anode and nickel-chrome cathode are immersed in a filling solution, a spontaneous voltage develops between the two electrodes. A membrane encapsulates the sensor. Oxygen that crosses the membrane is reduced at the cathode. As the oxygen is reduced, the voltage across the electrodes increases in proportion to the amount of oxygen that is consumed.

Less Contamination

Hydrogen sulfide contamination is greatly reduced because of the unique manufacturing process used in making the sensor. The Hach 5740 sc sensor outperforms similar systems at a greatly reduced price.

Complete Encapsulation

Fully-encapsulated construction protects the sensor’s built-in electronics from moisture and humidity problems, extending the working life of the sensor.

Measuring Range:

0.0 to 40.00 ppm (o to 40 mg/L) or 200% Saturation


Measurement: ± 2% of span


± 5% of span

Response Time at 200C:

To 90% in 120 seconds

Flow Rate:

0.5 cm/s (0.016 ft./s), minimum