Dissolved Oxygen Monitor SD-300


Enables High-precision Measurement and Monitoring of DO in Ultra-pure Water in the Semiconductor Industry
Ever-increasing semiconductor circuit densities require higher-quality ultra-pure water for cleaning wafers.
Minute DO (dissolved oxygen) in ultra-pure water oxygenates the wafer surfaces. To ensure high-quality ultra-pure water, DO levels must be strictly controlled. Horiba's SD-300 DO Monitor is the solution.
Created utilizing Horiba's semiconductor technologies, it provides effective high-quality, pure-water management. The SD-300 DO Monitor is lightweight and portable. It can be carried anywhere, enabling high-precision measurement of DO levels in ultra-pure water in the semiconductor industry.


  • Portable Design for Easy Operation Even in Narrow Spaces
    Compact, portable, and easy-to-use.
  • Achieve a Wide-range of Highly Sensitive Measurements
    Select the measurement range: 0 to 20 µg / L, 0 to 200 µg / L, 0 to 2 mg / L, or 0 to 20 mg / L. Switch between automatic and manual operation. Achieve highly sensitive measurements in the optimum range.
  • High-speed Response
  • Flat Panel Design for Use in Clean Rooms
  • Durable Internal Liquid Replacement Sensor
  • Standard-feature Analog / Serial Output

Manufactured by HORIBA Advanced Techno


Measuring object

Dissolved oxygen


Membrane Polarography

Measurement range

0 to 20 µg / L, 0 to 200 µg / L, 0 to 2 mg / L, 0 to 20 mg / L

Response time

30 s / 90 % (at 20 °C or more)


± 1 % of full scale

Temperature compensation

5 to 50 °C

Sample conditions


2 to 50 °C


0.02 to 0.2 Mpa

Flow rate

0.2 to 0.4 L / min.


Analog output

4 to 20 mA DC or 0 to 16 mA DC, isolated output load: 500 Ω max.

Contact output

Contact A output, contact capacity: 24 V DC, 0.1 A

Serial output

RS-232C output only



Electrical calibration or calibration with zero solution


Air (by placing a sensor in the air)

Ambient condition

Temperature : 0 to 45 °C, Humidity : 85 % max.


100 to 240 V AC (± 10 %), 50 / 60 Hz

Power consumption

Approx. 50 VA (at 100 VAC)


296 (W) X 110 (H) X 258 (D) mm (operation unit only)


Approx. 3.4 kg (operation unit only)

Length of extension cable between
operation unit and sensor unit

5 m (standard), 10 m (option)