Calibration, Verification, and Validation.

`In this article, we will explain the concepts of validation, verification, and calibration, which are essential for ensuring the proper functioning of a process or equipment. We will also provide some practical guidance on how to perform these tasks.

Validation, verification, and calibration have different meanings, but they share a common objective: to confirm that a system meets its intended requirements. The definitions of these terms are as follows:

• Validation: The process of demonstrating that a system fulfills its specified functional purpose.
• Verification: The process of confirming that a process or equipment operates in accordance with its defined operating specifications.
• Calibration: The process of adjusting the measurement accuracy of an instrument to match a known standard.

Validation: How to check the results?

Validation is usually performed to comply with some external standards or regulations, such as those imposed by the Environmental Protection Agency (EPA) for emissions control. Validation involves comparing the outputs of a process with the expected outcomes, and verifying that they are within acceptable limits. For example, in power plants and refineries, validation is used to ensure that the stack gas emissions meet the EPA requirements.

Verification: How to check the performance?

Verification is usually performed to ensure that a process or equipment is functioning correctly, according to the manufacturer’s technical specifications. Verification can be done as part of regular maintenance, or before installing a new instrument. Verification typically involves measuring some parameters of a process or equipment, such as flow rate or pressure, using a flow meter or a pressure gauge, and checking that they are within the specified range.

Validation and verification: How to do it?

The procedure for validation and verification is similar: measure a value and compare it with the expected range. If the value is within the range, the process or equipment is validated or verified. If the value is outside the range, the process or equipment needs to be adjusted or repaired.

Calibration: How to ensure accuracy?

Calibration is a two-step process that involves using a calibration standard to measure a flow value, and then adjusting the instrument under test to match the reading on the standard. A calibration standard is an instrument that has a known and traceable accuracy, such as those provided by the National Institute of Standards and Technology (NIST). There are two types of calibration standards:

• Primary standard: A universal measurement reference standard that is directly traceable to the International System of Units (SI).
• Transfer standard: An instrument that has been calibrated using a primary standard.

Calibration: Why is it important?

Calibration is important because it ensures that the measurement accuracy of an instrument is consistent with a known standard. This reduces the uncertainty and error in the measurement results, and improves the reliability and quality of the process or equipment.

The main takeaway is this:

• Verification confirms that a process or equipment operates according to its operating specifications. Calibration adjusts the measurement accuracy of an instrument to match a known standard.`