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Thermo Scientific™ Orion Star™ A325 pH/Conductivity Portable Multiparameter Meter

Accurately measure pH, conductivity and temperature with the Thermo Scientific™ Orion™ Star A325 pH / Conductivity Portable Meter for high performance in challenging field tests

$2,106.00 - $3,561.44


AC Adapter Universal 50-60 Hz, 100-240 VAC power adapter (sold separately, Cat. No. 1010003)
Accuracy (Conductivity) 0.5% of reading ±1 digit > 3 μS; 0.5% of reading ±0.01 μS ≤ 3 μS
Accuracy (mV) ±0.2 mV or ±0.05% of reading whichever is greater
Accuracy (pH) ±0.002pH
Accuracy (Resistivity) 0.5% of reading ±1 digit
View More Specs
Catalog Number Mfr. No. Description Includes Price Quantity    


thermo scientific™
Orion Star A325 pH/conductivity portable meter Star A325 pH/conductivity meter, 4 AA batteries, literature CD, printed quick start guide, computer interface cable and meter test certificate Each for $2,106.00


thermo scientific™
Orion Star A325 pH/conductivity portable meter kit with ROSS Ultra Triode low maintenance gel pH/ATC electrode, DuraProbe 4-cell conductivity sensor, solutions, meter armor and field case Orion STAR A325 pH/conductivity portable meter; 8107UWMMD Orion ROSS Triode pH/ATC gel-filled electrode with 3m cable; 013010MD Orion DuraProbe conductivity cell with 3m cable; 910410 pH 4.01 buffer pouches, pack of 10; 910710 pH 7.00 buffer pouches, pack of 10; 911010 pH 10.01 buffer pouches, pack of 10; 01100710 conductivity standard pouches, 1413 uS; 911110 rinse solution, pack of 10; protective armor with electrode holder; hard carrying case and batteries Each for $3,561.44
Description & Specifications


AC Adapter Universal 50-60 Hz, 100-240 VAC power adapter (sold separately, Cat. No. 1010003)
Accuracy (Conductivity) 0.5% of reading ±1 digit > 3 μS; 0.5% of reading ±0.01 μS ≤ 3 μS
Accuracy (mV) ±0.2 mV or ±0.05% of reading whichever is greater
Accuracy (pH) ±0.002pH
Accuracy (Resistivity) 0.5% of reading ±1 digit
Accuracy (Salinity) 0.5% of reading ±1 digit
Accuracy (TDS) 0.5% of reading ±1 digit
Accuracy (Temperature) ±0.1°C
Alarm Output High/low limit alarm, calibration due alarm
Backlight Option Yes, selectable
Battery Life 800 hours
Battery Type Four AA (included)
Calibration pH with calibration editing option, relative mV (RmV), ORP, conductivity with calibration editing option and temperature
Calibration Points 1 point relative mV (RmV) mode, 1 point ORP mode
Calibration Points (pH) 1 to 5
Cell Constant 0.001 to 199.9cm-1
Certifications/Compliance CE, TUV 3-1, FCC Class A
Channels 2
Data Management Details Transfer single, range or all data points to printer or computer
Calibration Points (Conductivity) Up to 5
Data Points 5000 with date and time stamp
Display Type Graphic LCD with backlight
Dimensions (L x W x H) 24cm x 10cm x 6.5cm (9.5 in. x 3.9 in. x 2.6 in.)
IP Rating IP-67
Languages English, Spanish, French, Italian, German and Chinese; Portuguese and Korean available with software update
Log Function Type Automatic data logging with Auto-Read and Timed measure modes; manual data logging with Continuous measure mode
Outputs USB, RS232
Range (Conductivity) 0.001 µS/cm to 3000 mS/cm
Range (mV) ±2000.0mV
Range (pH) -2.000 to 20.000pH
Range (Resistivity) 2 ohm to 100.0 meg-ohm
Range (Salinity) 0.06 to 80.00 psu, 0.05 to 42.00 ppt
Range (TDS) 0.001 to 200.0 ppm
Resolution (pH) 0.1, 0.01, 0.001pH
Inputs BNC (pH or ORP electrode), pin-tip (reference electrode), 8 pin MiniDIN (conductivity sensor with built-in temperature or ATC temperature probe)
Isopotential Point 7.000pH
Keypad Comprehensive with menu-specific function keys and dual purpose scroll/shortcut keys
Measurement Modes pH, mV, relative mV (RmV) or ORP with temperature; conductivity, TDS, salinity or resistivity with temperature
Memory Non-volatile memory preserves data log, calibration log and meter settings
Methods 10 per channel with password protection
Model Orion Star A325 pH/mV/RmV/ORP/Conductivity/TDS/Salinity/Resistivity/Temperature Portable Meter
Power Supply 4 AA batteries (included) or universal AC adapter (sold separately)
Range (ORP) ±2000.0mV
Range (Relative mV) ±2000.0mV
Range (Temperature) -5.0° to 105.0° C, 22.0° to 221.0° F
Relative Humidity Range 5 to 85 %, non-condensing
Resolution (Salinity) 0.01 psu or 0.01 ppt minimum, auto ranging
Resolution (TDS) 0.001 ppm minimum, auto ranging up to 4 significant digits
Resolution (Temperature) 0.1°C, 0.1°F
Salinity Measurement Modes Practical salinity (psu) or natural sea water (ppt)
Stability Selectable fast, medium, slow or Smart Stability setting; Selectable off or Automatic Smart averaging setting
TDS Factor Range Linear (0.02 to 9.99)
Temperature Compensation Linear, nLFn (non-linear ultra pure water), nLFu (non-linear ultra pure degassed water), EP (off with warning) or off
Temperature (English) Operating 41° to 113°F (ambient)
Temperature (Metric) Operating 5° to 45° C (ambient)
Temperature (Metric) Reference 5, 10, 15, 20, 25°C
Temperature Probe Calibration 1 point temperature offset calibration
Temperature Selection Manual or automatic with ATC temperature probe
Warranty 3 year meter warranty
Weight (English) 1.2 lb.
Weight (Metric) 0.5kg

Get high accuracy and premium performance everywhere you need it with the Thermo Scientific™ Orion™ Star A325 pH and Conductivity Portable Meter, designed for a wide range of pH, mV, ORP, conductivity, total dissolved solids (TDS), salinity, resistivity and temperature testing and field applications. Evaluate samples in the most demanding locations using this waterproof meter with IP67-rated housing. Use the two channels to measure pH and conductivity simultaneously or view each channel separately. Log up to 5000 data point sets with time / date stamp and transfer logs to a printer or computer.

Take your measurements at the source with our premium line of portable meters. The Thermo Scientific Orion Star A325 pH/conductivity portable meter offers an information-rich screen and user-friendly operation. This rugged, waterproof portable meter is ready to tackle the elements with you. Orion Star A325 pH/conductivity portable meters are designed to be easy to use, dependable field meters that offer advanced features and functions including a 5000 point date log with sample ID and user ID options, calibration and high/low limit alarms and password-protected measurement methods. 
  • Combined convenience with the benefits of a pH meter and conductivity meter in one easy-to-use system 
  • Measure pH, mV, relative mV or ORP with temperature on channel one and measure conductivity, TDS, salinity or resistivity with temperature on channel two
  • Easily view individual measurements on a full screen display and quickly toggle to a split screen display to view multiple measurements simultaneously
  • Perform up to a five point pH calibration using automatic buffer recognition of NIST or DIN buffer groups with choice to manually enter custom buffer values
  • Perform up to a five point conductivity calibration
  • Calibration editing option allows individual points to be fixed without a full recalibration
  • Auto-ranging conductivity values offer consistent readings across entire measurement range without need to recalibrate 
  • Use linear, non-linear, EP (USP) or off conductivity temperature compensation with 5, 10, 15, 20 or 25°C reference temperatures
  • Informative, easy-to-read backlit graphic display with clear onscreen instructions simplifies operation
  • Capture your critical readings with measurement stability indicator and selectable read modes – Auto-Read holds a stable reading, Continuous shows changing readings with hold option and Timed logs data at specific intervals
  • Data log collects and date/time stamps up to 5,000 measurement sets with optional sample ID and user ID
  • Calibration log stores ten most recent calibrations
  • Non-volatile meter memory ensures your data and settings are protected, even with loss of power
  • Orion Star Com software facilitates data transfer to a computer via USB or RS232 connections
  • 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

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