What is Metrology and How is It Used in Manufacturing?

Calibration is defined as aligning a tool’s measurement with a standard reading. For example, putting a thermometer in boiling water to ensure that it will measure correctly. If the thermometer reads 20℉ for a boiling pot of water, you know there’s a problem with the thermometer.

Per the International Organization for Standardization (ISO), metrology tools must be calibrated before use to read accurate information. Manufacturers can receive calibration certificates to validate that their metrology tools follow the ISO calibration standards.

Calibration is necessary for ensuring metrology tools work correctly, but traceability is needed for communication throughout manufacturing. In the case of metrology, traceability is the practice of sending data along the supply chain route so each manufacturer is up to date on a part’s history. This information is vital for quality control as it allows for quick recalls and uniform measurement across the manufacturing process.

Specific traceability regulations vary depending on the industry, but this generally means applying a mark or code that stores information like the calibration certificate, measurement data, the date the measurement took place, and manufacturing plant information.

Maintaining precision in metrology equipment requires systematic approaches to minimize errors. Temperature compensation systems automatically adjust readings as environmental conditions change. Built-in sensors monitor ambient conditions and apply corrections to ensure consistent results regardless of shop floor variations.

Regular checks ensure metrology systems stay within specifications. Automated systems detect issues before they cause problems, while built-in standards continuously verify accuracy during production.

For various production situations, each strategy offers unique benefits. Contact methods provide precise point measurements and outstanding accuracy for hard materials. With programmable measurement sequences, advanced CMM equipment efficiently manages intricate inspection procedures.

Optical systems excel in high-volume production settings and with sensitive components. 3D measurement systems simultaneously capture millions of data points, enabling thorough profile measurements.

Metrology equipment is increasingly required to function faster without compromising accuracy. Since production schedules often conflict with the requirement for comprehensive inspections, there is pressure to reduce measuring times. Strategic planning and automated systems that can keep up with production needs are necessary to strike a balance between speed and precision.

Part complexity continues to grow as products become more sophisticated and miniaturized. Industrial metrology systems must handle increasingly tight tolerances on smaller features. Multi-material assemblies present unique challenges, as different expansion rates and surface properties necessitate specialized measurement approaches. Multisensor measurement tools address these complex requirements with advanced analytical capabilities.

Measuring perfectly isn’t an easy process. Inaccurate measurements can happen from ambient vibration, high or low temperatures, debris, part movement, technician changes, or basic human error.

Ambient vibration can shake the machine, and high or low temperatures can cause the part to expand or contract. Debris can block a lens or attach to a part. Using contact measurement tools can accidentally change the positioning of a part or affect its geometry. Changing technicians and human error are hardly avoidable with handheld machines.

All of these factors are almost entirely unavoidable on the shop floor; however, some provisions of metrology tools lessen the effects on the measurement.

As previously mentioned, calibration and traceability are necessities for establishing quality control. KEYENCE's image dimension measurement systems (IM-X Series) and coordinate measurement machines (XM Series and WM Series) all use vision-based measurement. This enables the systems to only need to be recertified annually, rather than recalibrated, saving time and money for users. This method for recertification follows international and national standards that align with the measurement machine.

Most of KEYENCE’s metrology tools, except for the coordinate measurement machine probe, use non-contact methods for measurement. KEYENCE’s machines measure with the press of a button, so no human or tool comes in contact with the part.

Small or fragile parts can be placed on the stage and will resist any measurement errors from coming into contact with a device. Even more sensitive materials that deform or are easily contaminated (like food) can be measured by in-line sensors that do not require any stage.

Even the contact probe for KEYENCE’s CMMs still has a “wireless” aspect to it. The probe is completely untethered, allowing for easy in-machine measurement and portability to bring the measurement system wherever necessary.

KEYENCE's IM-X metrology tools are automated and have telecentric lenses and high-precision cameras that capture and measure a part the same way every time, regardless of the technician or part placement. KEYENCE XM and WM metrology tools have an easy-to-follow measurement procedure that any user can replicate, with parameters put in place to eliminate human error.

KEYENCE’s IM-X and CMMs (XM Series, WM Series) have built-in temperature sensors that nullify the effects of the environment for the most accurate measurements. The CMMs are designed to be durable for use even in harsh environments like manufacturing sites. A high-accuracy sensor in the camera unit diagnoses whether ambient vibrations will adversely affect measurement. They also have a temperature compensation function that ensures measurement targets are measured under the same conditions, just like a climate-controlled measuring room, even if the ambient temperature is not constant.