miniDOT® Logger Submersible water logger for measuring dissolved oxygen.

The miniDOT® Logger is a completely submersible instrument that logs dissolved oxygen and temperature measurements. The oxygen sensor is an optode that measures dissolved oxygen concentration in water through a fluorescence method. Data are recorded to an internal SD card. Operation of the miniDOT® Logger such as setting the time and sample interval can be accomplished via the USB cable.

Learn more about dissolved oxygen here.

Learn more about water temperature here.


  • Long-Lasting
  • Stable calibration
  • Records time, date and battery voltage
  • Anti-fouling available
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Commonly Used for Measuring

More about the miniDOT® Logger

  • User replaceable batteries
  • 300 Meter depth rating
  • Shipped calibrated
  • Portable and easy to use

The miniDOT Logger measures dissolved oxygen in water and is completely self contained. It includes an optical DO sensor, a temperature sensor, batteries and a micro SD memory card. The logger collects measurements of dissolved oxygen with an accuracy of +/- 5% and temperature to +/- 0.1 degrees C. All measurements are stored internally. Data can be offloaded to a computer via the miniDOT USB cable. Temperature range is 0 to 35 degrees C with an accuracy of +/- 0.1 degrees C. Oxygen range is 0 to 150% saturation with an accuracy of +/- 10 umole/L.

PME also has an anti-fouling wiper compatible with the miniDOT Logger. Increase your data longevity by using the PME wiper. More about the miniWIPER.

Product Design

The miniDOT Logger is constructed from a delrin plastic, which is a hard material that does not easily crack or break. All internal sensor components have been specifically designed to fit on the logger spine. The black sensor cover allows the user to easily grip and unscrew the top.

Logger Information & Sensor Specifications

The miniDOT sensor is an optode that measures lifetime-based luminescence quenching of a thin membrane. The sensing foil contains a coating that has a variable fluorescence that depends upon oxygen concentration in the surrounding water. The sensor is able to compute oxygen concentration in mg/L and record these measurements internally. Every miniDOT logger is calibrated at PME headquarters. Our unique method of calibrating oxygen sensors allow stability over years before re-calibration is necessary. The miniDOT Logger can sample any where between once every minute to once every hour. Contact PME for sample intervals outside this range.

Sample Interval Minutes Days of SamplingNumber of Samples
1 365 500K
10 365 + 52,000 +
60 365 + 8,000 +

Device Software

Software is provided with every miniDOT Logger and can be found on the micro SD card once connected to a computer. The software displays the miniDOT Logger files and creates visual plots to easily read oxygen measurements. The software also allows the user to set the internal clock and determine a sample rate.

Downloads & Resources

Product Software
Device Manuals
Product Brochures


Learn the basics of operating PME’s miniDOT Logger in this short video along with the anti-fouling options available. If you need support with your miniDOT Logger, reach out to our team.