VStar-technician-measuring-sample-270x195

Meet your pH and ORP sample analysis challenges in the lab or in the field

Whether you're looking for a simple pH meter on a budget, or a powerful pH meter that simultaneously measures other parameters, our pH meters are designed to help you tackle even the most complex pH measurements with confidence.

We offer simple, complete systems that are seamlessly integrated to help address your measurement needs both in the field and in the lab. Our benchtop pH meters are an ideal choice for dedicated pH testing in water, process, research, and QA/QC samples.

Browse our complete portfolio or let one of our experts help you make a selection.


pH Bench meterspH Portable metersMeeting regulatory requirements

Optimize your pH and ORP measurement process

High quality meters are essential to the critical, routine tasks you perform every day. Our portfolio of benchtop and portable meters for pH, ORP, and temperature analysis are designed to help you measure samples across a wide range of applications.

Whether working in food and beverage, pharmaceuticals, energy and power, education, government, or water and wastewater management, you can count on Thermo Scientific Orion pH/ORP meters to help you meet regulatory standards, help ensure quality control protocols are met, and accelerate your path from challenge to solution.

Learn more about the regulatory requirements our benchtop and portable meters can assist with.

Select your pH and ORP bench or portable meter

 

Premium

Advanced

Basic

 Orion Versa Star Pro pH
Bench Meter

(VSTAR10 series)
Orion Star 
A211 pH
Bench Meter

(STARA211 series)
Orion Star 
A111 pH
Bench Meter

(STARA111 series)
 Premium pH and ORP benchtop metersAdvanced pH and ORP benchtop metersBasic pH and ORP benchtop meters
 Versatile, high-performance laboratory measurement systemEasy to use, dependable laboratory metersEconomical, simplified
laboratory meters
Ideal for
applications in: 
Pharmaceuticals, biotechnology, food and beverage, industrialWater, 
wastewater,
chemical contract testing
Academic, 
environmental, 
power
pH range–2.000 to 20.000–2.000 to 20.000 –2.00 to 16.00
pH resolution0.001 / 0.01 / 0.10.001 / 0.01 / 0.10.01 / 0.1 
pH calibration pointsUp to 6Up to 5Up to 3 
mV, RmV modesYesYesYes
ORP modeYes Yes
Temperature Range-5 to 105°C
22 to 221°C
-5 to 105°C
23 to 221°C
-5 to 105°C
23 to 221°C
Backlit displayYesYes
Onscreen text promptsStep-by-step calibration and guided setup instructionsStep-by-step calibration and guided setup instructionsBasic calibration and setup prompts
Number of channels4, customizable with modules11
Stirrer probe inputs21
Data log2000 with date/time2000 with date/time50
Calibration log30 per mode10
Identification optionsElectrode ID, sample ID, user IDSample ID, user ID
Data export optionsUSB(2), RS232USB, RS232
Power supplyUniversal, 100–240 VAC, 50-60 Hz Cat. No. STARA-PWR)Universal, 100–240 VAC, 50–60 Hz (Cat. No. 1010003) or 4 AA batteriesUniversal, 100–240 VAC, 50–60 Hz (Cat. No. 1010003) or 4 AA batteries
  Increase your productivity by adding accessories to your benchtop or portable meter. Meter Accessories ›
 

Premium

Advanced

Basic

 Orion Star A321 pH Portable Meter
(Star A3210 series)
Orion Star A221 pH Portable Meter
(Star A2210 series)
Orion Star A121 pH Portable Meter
(Star A1210 series)
 Premium pH and ORP measurement portable metersAdvanced ORP and pH measurement portable metersBasic ORP and pH measurement benchtop meters
 Premium rugged,
easy-to-use
portable field meters
Advanced portable meters, easy-to-use, dependable field metersBasic portable meters, budget-friendly, simplified field meters
Ideal for
applications in:
pH, mV, ORP, and temperature testing, and field applicationsAdvanced pH analysis ideal for outdoor environments and field applicationsIP67-rated housing for rugged protection in outdoor environments
pH range–2.000 to 20.000 pH–2.000 to 20.000 pH2.00 to 16.00 pH
pH resolution0.1. 0.01, 0.001 pH0.1. 0.01, 0.001 pH0.1. 0.01 pH
pH relative accuracy±0.002 pH±0.002 pH±0.01 pH
pH calibration pointsUp to 5Up to 5Up to 3
mV modeYesYesYes
ORP modeYesYesNo
Range (temperature)–5.0° to 105.0°C,
22.0° to 221.0°F
–5.0° to 105.0°C,
22.0° to 221.0°F
–5.0° to 105.0°C,
22.0° to 221.0°F
Temperature compensationAutomatic or manualAutomatic or manualAutomatic or manual
Data points5000 with date and time stamp1000 with date and time stamp50
Data export optionsRS232, USBRS232, USB---
Power supply4 AA batteries: 800 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)4 AA batteries: 800 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)4 AA batteries: 2,000 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)
  Enhance your productivity with accessories for your benchtop and portable meters. Meter Accessories ›
 

Premium

Advanced

Basic

 Orion Versa Star Pro pH
Bench Meter

(VSTAR10 series)
Orion Star 
A211 pH
Bench Meter

(STARA211 series)
Orion Star 
A111 pH
Bench Meter

(STARA111 series)
 Premium pH and ORP benchtop metersAdvanced pH and ORP benchtop metersBasic pH and ORP benchtop meters
 Versatile, high-performance laboratory measurement systemEasy to use, dependable laboratory metersEconomical, simplified
laboratory meters
Ideal for
applications in: 
Pharmaceuticals, biotechnology, food and beverage, industrialWater, 
wastewater,
chemical contract testing
Academic, 
environmental, 
power
pH range–2.000 to 20.000–2.000 to 20.000 –2.00 to 16.00
pH resolution0.001 / 0.01 / 0.10.001 / 0.01 / 0.10.01 / 0.1 
pH calibration pointsUp to 6Up to 5Up to 3 
mV, RmV modesYesYesYes
ORP modeYes Yes
Temperature Range-5 to 105°C
22 to 221°C
-5 to 105°C
23 to 221°C
-5 to 105°C
23 to 221°C
Backlit displayYesYes
Onscreen text promptsStep-by-step calibration and guided setup instructionsStep-by-step calibration and guided setup instructionsBasic calibration and setup prompts
Number of channels4, customizable with modules11
Stirrer probe inputs21
Data log2000 with date/time2000 with date/time50
Calibration log30 per mode10
Identification optionsElectrode ID, sample ID, user IDSample ID, user ID
Data export optionsUSB(2), RS232USB, RS232
Power supplyUniversal, 100–240 VAC, 50-60 Hz Cat. No. STARA-PWR)Universal, 100–240 VAC, 50–60 Hz (Cat. No. 1010003) or 4 AA batteriesUniversal, 100–240 VAC, 50–60 Hz (Cat. No. 1010003) or 4 AA batteries
  Increase your productivity by adding accessories to your benchtop or portable meter. Meter Accessories ›
 

Premium

Advanced

Basic

 Orion Star A321 pH Portable Meter
(Star A3210 series)
Orion Star A221 pH Portable Meter
(Star A2210 series)
Orion Star A121 pH Portable Meter
(Star A1210 series)
 Premium pH and ORP measurement portable metersAdvanced ORP and pH measurement portable metersBasic ORP and pH measurement benchtop meters
 Premium rugged,
easy-to-use
portable field meters
Advanced portable meters, easy-to-use, dependable field metersBasic portable meters, budget-friendly, simplified field meters
Ideal for
applications in:
pH, mV, ORP, and temperature testing, and field applicationsAdvanced pH analysis ideal for outdoor environments and field applicationsIP67-rated housing for rugged protection in outdoor environments
pH range–2.000 to 20.000 pH–2.000 to 20.000 pH2.00 to 16.00 pH
pH resolution0.1. 0.01, 0.001 pH0.1. 0.01, 0.001 pH0.1. 0.01 pH
pH relative accuracy±0.002 pH±0.002 pH±0.01 pH
pH calibration pointsUp to 5Up to 5Up to 3
mV modeYesYesYes
ORP modeYesYesNo
Range (temperature)–5.0° to 105.0°C,
22.0° to 221.0°F
–5.0° to 105.0°C,
22.0° to 221.0°F
–5.0° to 105.0°C,
22.0° to 221.0°F
Temperature compensationAutomatic or manualAutomatic or manualAutomatic or manual
Data points5000 with date and time stamp1000 with date and time stamp50
Data export optionsRS232, USBRS232, USB---
Power supply4 AA batteries: 800 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)4 AA batteries: 800 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)4 AA batteries: 2,000 hrs. battery life (included) or optional universal, 100–240 VAC (sold separately)
  Enhance your productivity with accessories for your benchtop and portable meters. Meter Accessories ›

Explore versatile meters that combine testing capabilities

conductivity-meters

Measure pH, ion concentration, conductivity, dissolved oxygen, and temperature with a single, powerful meter. Our bench and portable multiparameter meters are designed to increase your productivity in the lab and in the field.

Research multiparameter meters


Meter accessories

Bench meter and portable meter accessories make help protect you and your instruments by simplifying repetitive tasks and providing secure storage and transportation.

View all meter accessories ›

pH-meters-accessories

International standards for regulatory compliance requirements: 

Parameter

EPA

SM

ASTM

ISO

China MEP

USP

EP

AOAC

Other

pH

EPA 150.14500-H+(B)D1293 (A,B)10523GB/T 6920<791>2.2.3973.41FDA - 21 CFR 114.90

pH of soil/solid waste

SW-846 9040C & 9045D D497210390GB/T15555  994.16 - 994.18USDA NRCS

Conductivity

EPA 120.1; SW-846 9050A2510 (B)D1125 (A)7888n/a<645>2.2.38973.40PSS-78 (salinity)

Dissolved oxygen

 4500-O (G)D888 (B, C)17289; 5814HJ506    

BOD

 5210 (B) 5815HJ505  973.44 

Fluoride

SW-846 92144500-F (C )D1179 (B)10359GB7484    

Ammonia

 4500-NH3
(D, E) 
D1426 (B)6778     

Nitrate

Orion 601; SW-846 9210A4500-NO3 (D)       

Sulfide

SW-846 92154500-S2 (G)D4658      

Cyanide

SW-846 92134500-CN (F)D2036 (A)      

Chloride

SW-846 92124500-Cl (D)D512 (C) GB11896    

Bromide

SW-846 9211        
 SM: Standard Methods for the Examination of Water and Wastewater. APHA, AWWA, WEF.
 ASTM: American Society for Testing and Materials
 ISO: International Organization for Standardization
 USP: United States Pharmacopeia
 EP: European Pharmacopeia
 China MEP: China Ministry of Environmental Protection
 AOAC: Association of Official Analytical Chemists
 NRCS: Natural Resources Conservation Service
 PSS-78: Practical Salinity Scale of 1978
 FDA: US Food and Drug Administration
 USDA: US Department of Agriculture

Featured pH measurement videos

Measuring pH in drinking water using the Thermo Scientific Orion Versa Star Pro benchtop meter.

Calibrating a Thermo Scientific Orion Star A series pH benchtop meter.

See our complete list of pH and ORP measurement offerings
pH and ORP Pocket Testers


 
Thermo Scientific Pocket Testers are ideal for on-the-go electrochemical testing.

Electrodes, Standards and Solutions



Quality pH electrodes, standards and solutions are available for a variety of body materials, body styles, fill types, references styles, and functions to meet your needs.

Virtual Demo

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Get answers to your top water analysis and water purification questions and see products in action. Sign up for a demo to learn about:

·  pH & Multiparameter Benchtop & Portable Meters
·  Electrodes (pH Electrodes, ISE, Conductivity, DO)
·  Potentiometric Titrators
·  Spectrophotometers
·  Water Purification Systems

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Support

Knowledge Base: Certificates of Analysis and SDS for Orion, ROSS, AQUAfast, AquaMate, and AquaSensors products.

Orion Meters Software and Upgrades
Thermo Scientific Orion benchtop and portable meters are designed to help deliver accurate, consistent results, day after day. Boost productivity by upgrading your software today.

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