Lab Manager Magazine's Independent Guide to Purchasing a pH Meter

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There are many different features of a laboratory pH meter to take into account before making your purchase, including accuracy, calibration type and number of calibration points, intuitive operation, expandability, reliability and value. This guide will take a look at three main selection criteria: benchtop or portable, pH detection range and pH resolution.

First, let’s look at where you will be using your pH meter: in the field, around your lab or sitting on your benchtop. Once you’ve finished reading this guide, head over to LabWrench.com to find all the latest pH meters.

Benchtop pH Meters

Benchtop pH meters offer the greatest versatility. Depending on which one you choose, these flexible models can provide the option to add built-in printers, data loggers, many different probe arms and accessories. Traditionally, the most precise, feature-packed meters have been benchtop models. Next, let’s look at the pH detection range of the meter and see if you require standard or extended:

A. A standard range, benchtop pH meter measures the standard pH scale of 0 to 14, which will cover most applications involving water-based solutions. Some pH meters read a smaller scale, such as 4 to 10, but they are not suitable for most lab environments, and therefore are not included in this guide.

B. An extended range, benchtop pH meter is used in applications requiring a base acid that falls outside the standard pH scale of 0 to 14. It could be either a negative reading such as -2 or as high as +20. Examples of these “super acids” include triflic acid and fluorosulfonic acid, which are commonly used in creating and maintaining organic cations that are useful as intermediate molecules in numerous reactions, such as those involving plastics and high-octane gasoline production and research.

Next, let's look at the resolution of your extended range pH meter to see which is best for you.

  • A pH resolution of 0.001 is ideal for highly sensitive lab applications where a pH reading of three decimal places is required. See the latest standard range benchtop pH meters with a resolution of 0.001 at LabWrench.com:
  • A pH resolution of 0.01 can be used in basic lab applications where a pH reading of two decimal places is all that is required. See a selection of standard range benchtop pH meters with a resolution of 0.01 at LabWrench.com:
  • A pH resolution of 0.1 can be used in basic lab applications where a ph reading of one decimal place is all that is required. See a selection of standard range benchtop pH meters with a resolution of 0.1 on LabWrench:

Portable Handheld pH Meters

Portable handheld pH meters in the past have lacked some of the sophisticated features of their benchtop counterparts, but now many of the portable models on the market are nearly as advanced. The new generation of portable meters can be a very attractive, if not required, option for lab or field use. Keep in mind that a portable model may carry a slightly higher price tag. Next, let’s look at the pH detection range of portable pH meters and see if you require standard or extended range:

A. A standard range, portable pH meter measures the standard ph scale of 0 to 14, which will cover most applications involving water-based solutions. Some ph meters read a smaller scale, such as 4 to 10, but they are not suitable for most lab environments and therefore are not included in this guide.

B. An extended range, portable pH meter is used in applications requiring a base acid that falls outside the standard ph scale of 0 to 14. It could be either a negative reading such as -2 or as high as +20. Examples of these “super acids” include triflic acid and fluorosulfonic acid, which are commonly used in creating and maintaining organic cations which are useful as intermediate molecules in numerous reactions, such as those involving plastics and high-octane gasoline production and research.

Next, let's look at the resolution of your extended range pH meter to see which is best for you.

  • A pH resolution of 0.001 is ideal for highly sensitive lab applications where a pH reading of three decimal places is required. Find the latest standard range portable pH meters with a resolution of 0.001 on LabWrench:
  • A pH resolution of 0.01 is suitable for most lab applications where a pH reading of two decimal places is acceptable. See the latest standard range portable pH meters with a resolution of 0.01 at LabWrench.com:
  • A pH resolution of 0.1 can be used in basic lab applications where a pH reading of one decimal place is all that is required. See LabWrench.com for the latest standard range portable pH meters with a resolution of 0.1:
Categories: Purchasing Guides

Published In

Managing Crisis Magazine Issue Cover
Managing Crisis

Published: December 1, 2010

Cover Story

Managing Crisis

Taking a look at the recent Gulf of Mexico oil well blowoutthe greatest industrial accident in historylab managers can find useful examples of similar decision-making failures that can occur in laboratory environments.