In the mid-1930s, Arnold Beckman created one of the first commercial pH meters— made originally to measure the acidity of lemons. Then an assistant professor of chemistry at the California Institute of Technology, he started selling his device as the Model G acidimeter, later known simply as the Model G pH meter. This work led him to start Beckman Instruments, known today as Beckman Coulter, which continues to make pH meters. Today, though, pH meters provide many features beyond those of the Model G. A meter is only one part of a pH system, because an appropriate electrode is crucial to the application. For example, if you are measuring samples with high solids or samples that are low in ionic strength, the pH electrode design will influence the overall system accuracy, maintenance schedule, and the expected life of the electrode. In general, today’s pH meters fall into one of three general categories: testers, “portable,” and benchtop.

Types of pH meters our readers are currently using or planning to buy for their labs:

  Currently Using Planning to Purchase
Benchtop pH Meter 53% 4%
Handheld pH Meter 22% 4%
In-line pH Meter 8% 2%
Tester pH Meter 3% 2%
Other 2% 0%

Thirteen percent of the respondents are using a solid state sensor pH Meter while another six percent are planning to make a purchase.

The methods for measuring pH survey respondents use in their labs:

Glass-electrode method 58%
Indicator methods 23%
Metal-electrode methods 9%
Hydrogen-electrode method 8%
Quinhydron-electrode method 1%
Antimony-electrode method 1%
Other 1%

The weighing applications respondents are using their lab balances for:

Pipette Calibration 25%
Differential Weighting 22%
Dynamic Weighing 21%
Mass Comparison 19%
Filter Weighting 11%
Other 3%

Seventy-two percent of lab professionals using pH meters are very satisfied with their products and have no issues.

Lab professionals using pH meters who are experiencing some problems identified the following challenges:

Frequent re-calibration 24%
Temperature-dependent 13%
Fragile—constant wearing and breaking of glass electrodes 12%
Unreliable/inaccurate measurement 9%
Maintenance-intensive 6%
Limited field applicability 4%
Other 2%
High labor costs 1%
Limited battery life 1%

The top 10 factors/features our readers look for when buying a pH meter:

  Important
Low maintenance/easy to clean 96%
Resolution and accuracy of the meter 95%
Ease of use 93%
Auto calibration with temperature
compensation
91%
Availability of supplies and accessories 88%
Longer-lived refillable electrode type 74%
Service and support 74%
Multi-level LCD display; display the
current measurement simultaneously
with the current temperature
71%
Heavy-duty and waterproof 71%
Detachable electrode probe 67%

 

For more information on pH meters, including useful articles and a list of manufacturers, visit www.labmanager.com/ph-meters Completed Surveys: 312

See the most recent survey results