• pH Portable Meter

pH Portable Meter

  • pH Range: -2.00 to 16.00, RH Range: 5 to 85%, non-condensing
  • mV Range: ±1600.0mV, Relative mV Range: ±1999.9mV
  • Temperature Range: 22.0° to 221.0° F, -5.0° to 105.0° C



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Take simple, routine pH, mV and temperature measurements with the Thermo Scientific Orion Star A121 pH Portable Meter, an easy-to-use and budget-friendly instrument for basic pH analysis in the field

Perform up to a three point pH calibration with easy recall of calibration points and slope. Quickly navigate setup menus and ensure consistent calibrations using the simple keypad layout and on-screen text prompts. This waterproof meter has an IP67-rated housing for rugged protection in outdoor environments.

Thermo Scientific Orion Star A121 pH portable meters are a simple, economical solution for your routine outdoor sample analysis. Featuring an emphasized measure key, selectable read modes and measurement stability indicator, our basic Orion Star A121 pH meters are designed to deliver measurements you can trust at an affordable price.

  • Measure pH, mV or relative mV with temperature
  • Perform up to a three point pH calibration with automatic buffer recognition or manual buffer entry
  • Simplified, easy-to-read display shows main measurement with temperature, stability indicator and electrode condition icon
  • User-friendly operation with basic calibration text prompts
  • Easily recall calibration data for procedure checks
  • Non-volatile memory preserves 50 point internal data log and meter settings, even with loss of power
  • Flexible power options with AA batteries or optional universal power adapter
  • IP67-rated housing is waterproof for rugged field operation
  • Meter kits include hard-sided field case and protective meter armor with electrode holders, adjustable wrist/belt strap and built-in meter stand
  • Meters offer CE, TUV 3-in-1 and FCC Class A certifications and 3-year replacement warranty


Many configurations, electrodes, consumables and accessories available on request.

StabilitySmart Stability and Smart Averaging
Resolution (Temperature)0.1°C, 0.1°F
Temperature Range22.0° to 221.0° F
-5.0° to 105.0° C
Temperature Probe Calibration1 point temperature offset calibration
Operating Temperature41° to 113°F (ambient)
5° to 45°C (ambient)
Warranty3 year meter warranty
Weight 2 lb.
0.5kg
Temperature SelectionManual or automatic with ATC temperature probe
AC AdapterUniversal 50-60 Hz, 100-240 VAC power adapter (sold separately, Cat. No. 1010003)
Accuracy (pH)±0.01pH
Accuracy (mV)±0.2 mV or ±0.05% of reading whichever is greater
Accuracy (Temperature)±0.1°C
Battery Life2000 hr.
Battery Type4 x AA
CalibrationpH, relative mV (RmV) and temperature
Calibration Points1 to 3
Data Management DetailsInternal data point memory
Channels1
Certifications/ComplianceCE, TUV 3-1, FCC Class A
LanguagesEnglish
Log Function TypeAutomatic data logging with Auto-Read measure mode; manual data logging with Continuous measure mode
Dimensions (L x W x H)24cm x 10cm x 6.5cm (9.5 in. x 3.9 in. x 2.6 in.)
Data Points50
Display TypeLCD
Resolution (pH)0.1, 0.01
Range (pH)-2.00 to 16.00
IP RatingIP-67
InputsBNC (pH or ORP electrode),8 pin MiniDIN (ATC temperature probe)
Isopotential Point7.00pH
KeypadSimple with highlighted measure key, scroll and shortcut keys
MemoryNon-volatile memory preserves log and settings
Measurement ModespH, mV or relative mV (RmV) with temperature
OutputsNone
Probe TypepH electrode, ORP electrode, ATC temperature probe (purchase separately)
Power SupplyUniversal AC adapter (included) or 4 AA batteries (sold separately)
Range (Relative mV)±1999.9mV
Relative Humidity Range5 to 85%, non-condensing
Resolution (mV)0.1mV
Range (mV)±1600.0mV