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Are you struggling to obtain accurate and reliable dissolved oxygen readings in your laboratory or field studies?

The Starter 400D DO Portable from Liberty Scales is the solution you need. Engineered with optical technology, this high-performance, low-maintenance meter eliminates the common hassles of traditional DO measurement. Perfect for lab and on-the-go analyses, the Starter 400D ensures that achieving precise measurements is simpler and more efficient than ever.

Key Benefits:

  • Optimized Accuracy: Offers a measurement range of 0.00 – 20.0 mg/L with resolutions up to 0.01 mg/L, ensuring precise readings with an accuracy of ±0.2 mg/L for values below 8 mg/L.
  • Ready on Demand: Equipped with an optical DO probe that requires no warm-up time, allowing for immediate readings without sample preparation.
  • Enhanced Visibility: A large, backlit color LCD provides clear visibility in low-light conditions, making it ideal for field applications.
  • Rugged Design: The durable IP54-rated ABS housing protects against dust and water, ensuring reliable performance in demanding environments.
  • Data Management: Stores up to 99 measurements and allows quick recall of the last calibration data, enhancing your productivity and record-keeping efficiency.
  • 5-Year Warranty: Enjoy peace of mind and long-term reliability with a comprehensive 5-year warranty on your investment.

When you choose the Starter 400D DO Portable, you are not just purchasing a meter but enhancing your ability to conduct water analysis confidently. This meter is a crucial addition to any collection of laboratory instruments, designed to offer you peace of mind with its reliability and ease of use. Feel the satisfaction of knowing that your dissolved oxygen measurements are handled accurately and efficiently, allowing you to focus on what truly matters in your research and analysis. Elevate your laboratory capabilities today with Liberty Scales' precision instruments.

Reach out to our dedicated team for further information and personalized assistance. Call us at (661) 888-1919 or email us at We're here to help you every step of the way!


  • Measurement Range: 0.00 – 20.0 mg/L(ppm); 0 – 50°C

  • Accuracy: ±0.2 mg/L(< 8 mg/L) or ±0.3 mg/L(8~20 mg/L); ±0.3 °C

  • Measurement Resolution: 0.01 mg/L; 0.1%; 0.1 °C

  • Display: Color LCD Graphics

  • Electrode: STDO21 (Included)

  • Accuracy DO: 0.2 ppm

  • Accuracy ± (Temperature): 0.3 °C

  • Battery Life: 12 hours with Disposable Batteries

  • Calibration: 2 Point

  • Dimensions: 5.91 in x 1.38 in x 3.54 in (150 mm x 35 mm x 90 mm) (LxHxW)

  • In-Use Cover: No

  • Measurement Range DO: 0 ppm – 20 ppm

  • Measurement Range (Temperature): 0 °C – 50 °C

  • Net Weight: 0.35 lb (0.16 kg)

  • Parameter: Dissolved Oxygen

  • Power: 4 AAA (LR03) Batteries (Included)

  • Resolution (DO): 0.01

  • Temperature compensation: Automatic

  • Temperature resolution: 0.1 °C

  • Temperature Sensor: 10 KΩ NTC

  • Working Environment: 41°F – 104°F, 80% RH, Non-condensing (5°C – 40°C, 80% RH, Non-condensing)
  • Free Shipping: Available across 48 continental USA. Extra charges may apply for residential, farm, or rural areas.
  • Express Shipping: Overnight and faster shipping options available at additional costs. Quotes obtainable via email.
  • Delivery Time: Typically 5 to 7 business days, varying by location and external conditions.
  • Tracking Information: Provided via email upon shipment. Accessible through account login. Additional information available upon request.
  • Return Policy: 15-day return period for unused, original condition products. A 25% restocking fee applies. Buyer covers original and return shipping costs.
  • Customer Support: Contact at (661) 888-1919 or for queries or concerns about shipping.