Orion Star A321 pH Portable Meter

  • High Range pH Applications pH measurement range from -2.000 to 20.000
  • Large Memory Capacity Non-volatile memory can store up to 5000 time and date stamped data points
  • Informative Display Information displayed includes pH/mV/RmV and temperature along with electrode status, time, date, sample ID, user ID and calibration points
  • Warranty A321 is covered by a 3 year meter warranty
Product Options


The Orion A321 Portable pH Meter is capable of giving advanced readings when working on location. The informative display shows pH/mV/RmV and temperature along with electrode status, time, date, sample ID, user ID and calibration points.

The pH meter has the capacity to hold up to 5000 data points time and date stamped. Up to 5 point pH calibration which automatically recognizes USA/NIST and DIN buffers.

Additional advanced features are stability and averaging options which give further options allowing for laboratory results whilst on site. AUTO-READ locks stable readings on screen and the ready indicator highlights when readings are stable. Timed data gatherings enable data to be collected at specific time intervals. Multilanguage options allow the meter to read in English, Spanish, French, Italian, German and Chinese.

Standard features include easy data transfer and software updates by using the USB, RS232 ports plus the complimentary data analysis software. Waterproof, IP67-rated housing and the ability to run from batteries which give 800 hours of power or though a universal power adapter sold separately allows for this meter to be used anywhere and fully portable.

Covered by a 3 year warranty replacement.

Manufactured by: Thermo Scientific
Model: Orion Star A321 pH Portable Meter

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


pH monitoring
ORP monitoring


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
Range -5 to 105 °C, 23 to 221°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
ATC Probe 8-pin mini-DIN
Output RS232, USB
AC Adapter Optional - universal, 100-240 VAC
Battery Power Included 4 AAs
Battery Life 800 hrs


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