Go Direct® Optical Dissolved Oxygen Probe (GDX-ODO)

Specifications and User Guide

Note: This information is for the Go Direct Dissolved Oxygen Sensor. For information about Vernier Optical DO Probe (ODO-BTA) see Optical DO Probe Troubleshooting and FAQs.

Troubleshooting

General: Press the power button on the sensor to turn it on. Connect your sensor as described in the Getting Started instructions for your device. (The green LED will flash to indicate the sensor is connected.)

  • Primary Test: It should read approximately 100% on the Saturation channel when in air-saturated water or water-saturated air.

Additional Troubleshooting

MAINTENANCE

Specifications

  • Range: 0 to 20 mg/L, 0 to 300%
  • Accuracy
    ⚬ mg/L: ±0.1 mg/L (< 10 mg/L); ±0.2 mg/L (> 10 mg/L)
    ⚬ %: ±2% (below 100%); ±5% (above 100%)
  • Accuracy with calibration reset
    ⚬ mg/L: ±0.2 mg/L (< 10 mg/L); ±0.4 mg/L (> 10 mg/L)
    ⚬ %: ±1% (below 100%); ±5% (above 100%)
  • Measurement Type: Luminescent
  • Response Time: 90% of final reading in 40 seconds
  • Temperature Range: automatic from 0 to 50°C
  • Pressure Range: automatic from 228 mmHg to 1519 mmHg
  • Minimum sample flow: none required
  • Dimensions
    ⚬ Sensing shaft outer diameter: 12 mm.
    ⚬ Overall sensor: 22.7 cm long; 3.7 cm wide (widest part of the body)
  • Connections
    ⚬ Wireless: Bluetooth® v4.2 (wireless range 30 m unobstructed)
    ⚬ Wired: USB 2.0 full speed
  • Battery: 650 mA Li-Poly
    ⚬ Battery Life (single, full charge): ~24 hours continuous data collection
    ⚬ Battery Life (lifetime): 2 – 5 years (typical)

Calibration

The sensors on the Go Direct Optical Dissolved Oxygen sensor are factory calibrated and do not require calibration by the user. If the DO Concentration or DO Saturation sensor channels are not reading accurately, a reset can be done using a one-point calibration. To do a reset, follow the instructions below.

  1. Fill the storage bottle to the top of the sponge with distilled water.
  2. Insert the probe into the storage bottle and make sure it is positioned vertically so that the tip is not in contact with the sponge or water.
  3. Start the software and identify your probe, if necessary.
  4. Keep the probe in a vertical position for a minimum of 60 seconds.
  5. Click or tap the sensor meter for the channel you want to reset (DO Concentration or DO Saturation).
  6. Choose calibrate, and follow the instructions on the screen.

Note: the temperature and pressure sensors cannot be calibrated by the user.

DO Salinity

The salinity correction is automatically set for 35 ppt. To change the correction, click or tap the DO Salinity meter, choose calibrate, and enter the actual salinity concentration, in ppt. Click or tap Keep, then click or tap Done.

Battery Troubleshooting

  1. If the sensor can be turned on when connected by USB but not when disconnected from USB, it is likely that the battery just needs to be charged.
    ⚬ Try charging the sensor for several hours.
  2. If the sensor still won’t turn on when disconnected from USB, try swapping the battery with a working sensor to see if the problem follows the battery or stays with the sensor.
    ⚬ If the problem stays with the sensor, the battery is probably not the issue.
    ⚬ If the problem follows the battery, the battery has likely reached its end of life.
  3. If the battery is indeed at the end of its life, the sensor cannot be used even if connected by USB, so the battery will need to be replaced. Go Direct® 650 mAh Replacement Battery (GDX-BAT-650)
  4. See How do I replace the battery in a Go Direct Wand-Style Sensor? for more information (including a video).

Rechargeable batteries are covered by a one-year warranty.
Batteries should last two to five years in typical use.

Related Products

Replacement Parts

Published: November 11, 2019. Updated: July 17, 2025.