What's the difference between Validation, Verification and Calibration?

Tuesday, 20th August 2024

Validation, verification, and calibration all aim to ensure that a process functions correctly according to its intended purpose. Below, we’ll explore these three related but distinct processes and provide guidance on how to validate, verify, or calibrate your system effectively.

Term definitions

At their core, these terms can be defined as follows:

• Validation: Ensuring that a system achieves its intended functional objectives.
• Verification: Confirming that a process or equipment operates within its specified parameters.
• Calibration: Guaranteeing that an instrument's measurements align with a recognized standard for accuracy.

Validation - Are the outcomes as expected?

During validation, the user assesses whether the outputs of a process meet predetermined standards. These standards may be set by external regulations or internal benchmarks. For example, in power plants and refineries, validation involves ensuring that stack gas emissions comply with EPA regulations.

Verification - Is the device functioning properly?

Verification aims to ensure that equipment or processes operate according to the manufacturer's specifications. This verification can occur during routine maintenance or before installing newly acquired instruments. This could look like temporarily integrating a flow meter into a process to measure parameters such as flow rate or pressure.

Executing Validation and Verification

Despite their differing objectives, validation and verification follow a similar protocol: obtaining a value and assessing if it falls within predefined parameters. Portable mass flow meters like Alicat’s MB Series offer a convenient solution for swift validation and verification tasks.

• These battery-operated devices have a lifespan of up to 18 hours, enabling quick checks across multiple processes or instruments.
• The device's ability to measure multiple variables simultaneously allows for the validation or verification of process pressure, mass flow rate, or volumetric flow rate, all using a single device.
• Configurations with low pressure drops cater to systems with minimal pressure or help minimize the impact on the system.

In cases where a single device's flow range is insufficient, Alicat’s PCU (Portable Calibration Unit) can be utilized. These units incorporate three high-precision, battery-powered mass flow meters, designed for rapid and straightforward verification of various process components operating across a broad spectrum of flow rates.

Alicat MB - Portable Gas Mass Flow Meter

With this portable device you can take on validation and verification tasks anywhere you need.

Alicat PCU - Portable Calibration Unit

When a single device would be insufficient, verify and validate a number of different processes with this PCU unit.

Calibration - Ensuring Continued Accuracy

Calibration entails a two-step process where users initially employ a calibration standard to measure a flow value and then adjust the device under test to match the standard reading.

Two distinct types of standards exist:

• Primary standards serve as universal measurement references, exemplified by those established by the National Institute of Standards and Technology (NIST).
• Transfer standards are instruments directly calibrated using primary standards.

Due to the high cost associated with primary standards, transfer standards are commonly preferred. Alicat’s high-accuracy mass flow meters and pressure transducers serve as dependable transfer calibration standards for flow and pressure calibrations.

Conducting Calibration

When selecting instruments for calibration, accuracy requirements and operating range are pivotal considerations.

• A single Alicat M Series flow meter is capable of calibrating most common devices, boasting NIST-traceable accuracy of ±0.5% of reading or ±0.1% of full scale, covering a flow measurement range from 0.01% to 100% of full scale (10,000:1).
• For calibrations demanding higher accuracy, an additional device may be necessary, either comprising two high-accuracy mass flow meters or one high-accuracy meter paired with a high-accuracy controller.
• Calibrations necessitating wider operating ranges may require a portable calibration unit offering a 100,000:1 operating range.

Get in touch

PCT's dedicated application engineers are readily available to discuss your specific application needs and recommend the most suitable solution for your process validation, verification, or calibration requirements. You can call 01953 669930 or email sales@pctflow.com. You can also find out more information on our page explaining our service centre.

Related article

Annual Calibration explained

Posted by Peter Hill, Service and Operations Manager