Ensure accurate and reliable measurements in your laboratory and research locations
Our benchtop pH and ORP (Oxidation-Reduction Potential) meters are designed to address a variety of measurement requirements for dependable performance, accuracy, and reproducibility. Identify the best match based on your required features, performance specifications, and budget.
Which benchtop pH and ORP meter is right for you?
Premium | Advanced | Basic | |
|---|---|---|---|
| Orion Versa Star Pro pH Benchtop Meter (VSTAR10 series) | Orion Star A211 pH Benchtop Meter (STARA211 series) | Orion Star A111 pH Benchtop Meter (STARA111 series) | |
 |  |  | |
| Versatile, high-performance laboratory measurement system | Easy to use, dependable laboratory meters | Economical, simplified laboratory meters | |
| Ideal for applications in: | Pharmaceuticals, biotechnology, food and beverage, industrial | Water, 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 resolution | 0.001 / 0.01 / 0.1 | 0.001 / 0.01 / 0.1 | 0.01 / 0.1 |
| pH calibration points | Up to 6 | Up to 5 | Up to 3 |
| pH calibration modes | Auto buffer recognition with option to edit values | Auto buffer recognition with option to edit values | Auto buffer recognition or manual buffer entry |
| Automatic buffer sets | USA/NIST, DIN or custom | USA/NIST or DIN | USA/NIST or DIN |
| mV, RmV modes | Yes | Yes | Yes |
| ORP mode | Yes | Yes | — |
| Display type | Adjustable color graphic LCD | Graphic LCD | Fixed segment LCD |
| Backlit display | Yes | Yes | — |
| Onscreen text prompts | Step-by-step calibration and guided setup instructions | Step-by-step calibration and guided setup instructions | Basic calibration and setup prompts |
| Keypad | Numeric with menu-specific function keys | Comprehensive with menu-specific function keys | Simple with highlighted measure key |
| Number of channels | 4, customizable with modules | 1 | 1 |
| Included modules | 1 x VSTAR-PH | — | — |
| Stirrer probe inputs | 2 | 1 | — |
| Measure read modes | Auto-read, continuous, timed, single-shot | Auto-read, continuous, timed | Auto-read, continuous |
| Methods | 10 per channel | 10 | — |
| Data log | 2000 with date/time | 2000 with date/time | 50 |
| Calibration log | 30 per mode | 10 | — |
| Identification options | Electrode ID, sample ID, user ID | Sample ID, user ID | — |
| Alarms | Set point, high/low limit, calibration due | High/low limit, calibration due | — |
| External device output | USB(2), RS232 | USB, RS232 | — |
| Certifications | IP-54, CE, TUV 3-in-1, FCC Class A | IP-54, CE, TUV 3-in-1, FCC Class A | IP-54, CE, TUV 3-in-1, FCC Class A |
| Power supply | Universal, 100–240 VAC, 50-60 Hz Cat. No. STARA-PWR) | Universal, 100–240 VAC, 50–60 Hz (Cat. No. 1010003) or 4 AA batteries | Universal, 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 › | |||
Confidence in your pH measurements
The accuracy and reliability of your measurements depend on the instrumentation you use. Learn more about the other products offered as part of this portfolio.
Portable
pH and ORP Meters
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Are you taking samples in the field and bringing them back to the lab? Our portable pH meters are designed to offer simple and accurate pH measurements for your on-the-go measurements. Find the ideal portable meter to complement your laboratory application.
pH Electrodes
and Probes
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Our extensive assortment of quality pH electrodes, sensors, and probes are designed to make your complex measurements routine, reliable, and accurate—in the lab or in the field. They are available in a variety of body materials, body styles, and sample requirements. Find the best electrode for your application.
Buffers and
Solutions
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We offer a variety of pH buffer solutions, pH electrode storage solutions, electrode cleaning solutions, lab buffer kits, and electrode filling solutions for every application. All Thermo Scientific Orion pH lab buffers and solutions are traceable to NIST reference materials. Find the buffers and solutions necessary to complete your measurements.
Featured pH measurement videos
Calibrating a Thermo Scientific Orion Star A series pH benchtop meter
Measuring pH in drinking water using the Thermo Scientific Orion Versa Star Pro benchtop meter
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.
