Difference Between pH Meter and pH Paper

Table
  1. What is a pH meter?
  2. What is a pH paper?
  3. Difference between pH meter and pH paper:

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

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

What is a pH meter?

The pH meter is an electronic device used to determine the pH of the sample solution. It has an electrode (glass electrode or reference electrode) connected to the meter, which can measure the small voltage normally. 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 known as a potentiometric pH meter because it measures the electrical potential difference between a pH electrode and a reference electrode. Depending on the pH level, a color change indicator, pH paper, or litmus paper can be used to get an approximate pH of the sample. The precision of these types is limited and can be complex to interpret correctly. Therefore, a pH meter is more widely used to determine the pH of a sample solution.

What is a pH paper?

A pH paper is a piece of paper used to determine the pH of a solution and comes in the form of strips saturated with pH indicators. It changes color on contact with the sample solution under test, depending on the pH of the sample solution.

It is a fast, simple and reliable way to measure acidity or alkalinity. Typically a drop of the solution can be placed on the pH strip or dipped into the solution to see the color change from the reference scale (01-14).

Difference between pH meter and pH paper:

  • The main difference between a pH meter and 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 strip of paper.
  • The digital pH meter records pH values ​​continuously and repeatedly and even allows automatic recording of measurements, while the paper strip can only be used for manual measurement.
  • A pH meter requires more sample to immerse the electrode, while a pH paper only requires a single drop to detect a color change.
  • A pH meter is an expensive method to determine the pH of any solution compared to paper, while a pH paper is an inexpensive method compared to a pH meter.
  • Readings provided by a pH meter are accurate and repeatable, while test strip results may vary as the strips are handled, different people perceive colors differently and may interpret color comparison in different ways .
  • pH meter has a longer shelf life, while pH paper has a shorter shelf life, test strips contain reagents that degrade over time.
  • pH meters require regular maintenance and calibration which is expensive and time consuming, while pH paper saves time and money.
  • A pH meter that can provide computerized digital data in the form of software or printers and is recommended for auditing and regulatory compliance, whereas results provided by strips are not acceptable for this purpose.
  • A pH meter is usually chosen over a pH test strip because a pH meter often offers better resolution than pH strips and is generally much more accurate and precise than pH test strips.

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