Chrominfo: Difference between pH meter and pH paper

The major difference between the pH meter and pH paper is that the pH paper used to determine the pH is not as accurate as a pH meter, which determines the exact pH of the sample.

The pH is an important factor that specifies the acidity or alkalinity of the solution it measures the hydrogen ions (H +) concentration in the solution. The pH determines by the various method in which the electrometric method and colorimetric method are used. Universal indicator, pH meter, pH paper, and litmus paper (blue or red), etc. are the fastest and easiest way to determine pH.

What is a pH meter?

The pH meter is an electronic apparatus that is utilized to determine the pH of the sample solution. It has an electrode (glass electrode or reference electrode) attached to the meter, which can usually measure the small voltage. Since, it is calibrated with standard buffer solutions such as pH 07, pH 04, and pH 09.20, it gives accurate results on a scale of pH 0 to 14.

It is also referred to as a potentiometric pH meter since it measures the difference in electric potential between a pH electrode and a reference electrode. Depending on the pH level, a color-changing indicator, pH paper, or litmus paper can be used to get an approximate pH of the sample. The precision of such types is limited, and it can be complex to interpret correctly and hence a pH meter is most widely used to determine the pH of a sample solution.

What is a pH paper?

A pH paper is a piece of paper that is used to determine the pH of a solution and comes as strips that are saturated with pH indicators. It changes color when it comes into contact with the sample solution being tested, according to the pH of the sample solution.

It is a quick, simple, and reliable way of measuring acidity or alkalinity. Usually, a drop of the solution can be placed on the pH strip or it is immersed in the solution to see the color change compared to the reference scale (01-14).

Difference between pH meter and pH paper:

The major difference between a pH meter and a pH paper is that the paper used to determine the pH is not as accurate as a pH meter, which determines the exact pH of the sample.
As the name suggests, a pH meter is an instrument while pH paper is a paper strip.
The digital pH meter records pH values continuously and repeatedly and even allows automatic recording of measurements, whereas the paper strip can be used for only one manual measurement.
A pH meter requires more sample quantity to immerse the electrode, while a pH paper requires only a drop to detect a color change.
A pH meter is an expensive method of determining the pH of any solution as compared to paper, while a pH paper is an economical method as compared to a pH meter.
The readings provide by a pH meter are accurate and reproducible, while test strip results can vary depending on how the strips are handled, Different people perceive colors differently and may interpret color comparison in different ways.
pH meter has a longer shelf life, whereas pH paper has a shorter shelf life, test strips contain reagents that degrade over time.
pH meters require regular maintenance and calibration, which is time and cost consuming, while pH paper saves time and cost.
A pH meter apparatus that can provide computerized digital data in the form of software or printers and is recommended for audit and regulatory compliance, whereas the results provided by strips are not acceptable for that purpose.
Generally, a pH Meter is chosen instead of a pH Test strip since a pH meter often gives better resolution than the pH strips, and it is normally considerably more exact and accurate than test strips.