Orion Star A326 pH / Dissolved Oxygen Portable Meter

  • High Range pH Applications pH measurement range from -2.000 to 20.000
  • High Range DO Applications Dissolved oxygen (concentration) measurement range from 0 to 90 mg/L
  • Non-Volatile Memory Memory capacity to store up up 5000 time and date stamped data points
  • Warranty A326 pH/DO meter is covered by a 3 year replacement meter warranty
Product Options


The Star A326 portable water quality meter measures pH and dissolved oxygen, automatically accepting of Orion polarographic and RDO optical/luminescence-based probes. DO results are guaranteed to be accurate due to automatic temperature, manual salinity and automatic/manual barometric pressure correction. DO calibrations can be carried out using water-saturated air, air-saturated water, a Winkler titration or zero point calibration. Up to 5 point pH calibration with automatic recognition for USA/NIST and DIN buffers and the advanced feature of being able to fix pH calibration errors using calibration editing without the need for a complete recalibration makes for easy use.

Transfer of data and updated software is easily accessed using the USB and RS232 ports and data analysis software. The large backlit graphic LCD displays individual pH/mV/RmV or dissolved oxygen in percent saturation or concentration results with temperature, or all the results can be viewed at once. Laboratory results are given with stability and averaging options which allow further options for enhanced accuracy. 5000 data points time and date stamped can be held in the memory.

Standard features of the Orion Star A326 pH/RDO/Dissolved Portable Meter are it is fully waterproof, housed with IP67-rated housing. It has Multilanguage settings in English, Spanish, French, Italian, German and Chinese and plain language prompts. AUTO-READ™ means readings will never be missed with the additional benefit of stable readings being locked on screen and an indicator alert highlight when readings are stable. Timed data allows readings to be gathered at timed intervals.

The final benefits of this piece of equipment are it can be powered either by batteries which give up to 800 hours of operation of by a universal power adapter sold separately to use AC power and is covered by a 3 year replacement warranty.

Manufactured by: Thermo Scientific
Model: Orion Star A326 pH / Dissolved Oxygen Portable Meter

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


Still water applications


Range -2.000 to 20.000
Resolution 0.1, 0.01, 0.001
Relative Accuracy ±0.002
Calibration Points Up to 5
Calibration Editing Yes
Range ±2000.0 mV
Resolution 0.1
Relative Accuracy ±0.2 mV or ±0.05 % of
reading whichever is greater
EH ORP Mode Yes
Dissolved Oxygen -
Concentration - Polarographic
Range 0 to 90 mg/L
Resolution 0.01, 0.1
Relative Accuracy ±0.2
% Saturation - Polarographic
Range 0 to 600
Resolution 0.1, 1
Relative Accuracy ±2 %
Concentration - RDO
Range 0 to 50 mg/L
Resolution 0.01, 0.1
Relative Accuracy ±0.1 mg/L up to 8 mg/L;
±0.2 mg/L from 8 to 20 mg/L;
10 % of reading from
20 to 50 mg/L
% Saturation - RDO
Range 0 to 500
Resolution 0.1, 1
Relative Accuracy ±2 %
Manual Barometric Pressure Correction 450.0 to 850.0 mm Hg
Manual Salinity Factor Correction 0 to 45 ppt
Calibration Features Water saturated air,
air saturated water, manual (Winkler) and zero point
Probe Type Polarographic or RDO
Range 0 to 50 °C, 32 to 122 °F
Resolution 0.1
Relative Accuracy ±0.1
Offset Calibration 1 point
Number of Points 2000 with time and date stamp
Log Function Manual, ready (includes AUTO-READ™), timed
Log Edit Delete individual points, group of points or all
pH Electrode BNC, reference pin
DO with Temp. Probe 9-pin mini-DIN
Output RS232, USB
AC Adapter Optional universal, 100-240 VAC
Battery Power Optional 4 AAs
Battery Life 800 hrs