Dimensional Measurement Blog

Dimensional inspection is used in a broad range of industries for a wide variety of applications. However, there are some common reasons why this type of measurement is used. Whether the objective is to compare a prototype to a drawing or to ensure that a finished product meets certain standards, the fundamentals of dimensional inspection remain the same. Highly accurate measurements are taken to determine how closely an object matches its originally intended dimensions.

In general, if dimensional measurement is required, the results must be both accurate and precise. Although multiple techniques and countless applications exist, there are four main categories of dimensional inspection.

Four Common Dimensional Inspection Applications

1. First article inspection. Implementing a manufacturing process requires extreme attention to detail, especially if the process is new or if the equipment has been specially designed. First article inspection is required to ensure that the equipment was properly installed and calibrated, and to verify the manufacturing process. Dimensional measurement is used to compare the first objects from the manufacturing line to 3-D CAD models or other specifications.
2. Quality control. When objects coming off a manufacturing line must meet certain quality standards, measurement equipment is used to confirm that the dimensions fall within the required tolerance levels. In some cases, when the tolerance levels are more rigorous, each object is measured automatically. In other cases, batches might be spot-checked for quality.
3. Regulatory compliance. In industries for which regulatory compliance is necessary, dimensional measurement ensures that the required specifications are met. Regulatory bodies such as the FDA or FAA often have requirements regarding the dimensions of certain components. 
4. High-precision engineering. When creating a larger assembly from smaller parts, high precision is often required. If a minor flaw or inconsistency can impact an entire process, ensuring that such imperfections do not exist is critical. 

Employing dimensional measurement in these scenarios offers many benefits, including reduced liability, improved quality, and lower costs.

If you need dimensional inspection services for your business, contact the professionals at Q-PLUS Labs. We provide outsourced measurement services for a range of industries including manufacturing, aerospace, medical, and more. Schedule a consultation today to learn more about how we can help you with your dimensional measurement needs.

How does your company use dimensional inspection?

 

Purchasing dimensional inspection equipment requires making a big decision, and in most cases a significant financial investment. It is important to be certain that the equipment you buy will serve its intended purpose and provide the results you need.

Because there are so many different types of equipment that can be used for a broad range of purposes, it helps to know what questions to ask before you buy.

11 Dimensional Inspection Equipment Questions You Need to Ask

1. What sensor type do you need?
   
   Depending on the surface characteristics of the objects you intend to measure, you may need either a contact sensor or a non-contact sensor. Within each of these two categories are several other options and different sensor types. The more you know about the objects you will be measuring, the better able you will be to select the right types of dimensional inspection equipment.
   
   
2. What tolerance levels are required for your application?
   
   There is a big difference between replicating an antique to sell in a gift shop and mass producing components that will be used in a medical device. In the former case, a certain amount of inaccuracy is tolerable, while in the latter case the requirements are more stringent. Make sure you know how precise you need to be, especially if you have to maintain regulatory compliance.
   
   
3. Does your equipment need to be portable?
   
   Do you need a machine that will always sit at the end of a production line, or do you need a more portable unit that can take measurements in the field?
   
   
4. What size(s) are the objects you need to measure?
   
   Some objects are small enough to be put into a machine, while others are simply too large or heavy. On the other hand, objects that are on the nano scale will require specialized equipment.
   
   
5. What shape(s) are the objects you need to measure?
   
   Does your object have internal geometry that you need to measure? Bore holes, threads, and other complex geometry cannot always be measured by certain types of dimensional inspection equipment or without certain accessories.
   
   
6. How fast do you need results?
   
   Measuring the occasional prototype is a different scenario than inspecting every component that comes off a production line. It is important to know how quickly you will need results so you can purchase a machine that is capable of meeting your needs.
   
   
7. Does your equipment need to be automated?
   
   Some dimensional inspection equipment can be automated, but not all of it can be. If this is an important factor for your application, make sure it is a high priority in your purchasing decision.
   
   
8. Who will be using the equipment?
   
   Ease of use should be considered if you are weighing multiple options. Will you need to hire new staff or train employees to use this new equipment? Does your budget support that?
   
   
9. What is required to maintain the equipment?
   
   High-precision measurement equipment needs to be properly set up, regularly maintained, and periodically calibrated. Does your staff have the skills to do this, or can you outsource it?
   
   
10. How durable and reliable is the equipment?
    
    Dimensional inspection equipment is an investment. It is important to compare multiple manufacturers and work with an expert who has experience will all of them.
    
    
11. What is your budget?
    
    Perhaps one of the most important factors is your budget, however, be sure to weigh all of the above before you make a decision.

If you would like to learn more about selecting the right dimensional inspection equipment for your application, download our free guide. You can also schedule a consultation with one of our dimensional inspection experts who can walk you through the entire process. Contact us today to schedule an assessment.

What type of dimensional inspection equipment are you looking for?

Dimensional inspection can be performed with a wide variety of methods and equipment, depending on the object being measured. When selecting equipment, remember the cardinal rule of dimensional inspection: The object being measured cannot be altered during the measurement process. This means that some objects cannot be touched because the resulting measurements will be inaccurate.

When touching an object with a probe will alter its dimensions, non-contact sensors must be used during the measurement process. Cases when this is appropriate include when the object is:

• Soft
• Elastic
• Very small
• Fragile

Examples include objects such as micro-gears, rubber gaskets, prosthetics made of soft plastic, or a fragile antique with a delicate surface.

Non-Contact Sensors for Dimensional Inspection

Several types of non-contact sensors can be used for dimensional inspection, including:

• 3D scanners. There are two main types of 3D scanners: those that use structured light and those that use lasers. In both cases, light is projected onto the surface of an object and measurements are made based on the reaction of the light. With structured light, the distances are measured using the distortion of pixels, and with lasers, the reflection is used to triangulate distances. Clearly, the surface characteristics are a significant factor in determining whether 3D scanning should be used.
• Optical comparators. When light is projected onto an object, its resulting shadow or silhouette can be used to take measurements or compare the shape to the specifications. Fiber optic technology can also be used for edge detection.
• Vision systems. This type of equipment uses a similar concept to optical comparators in that light is projected onto a screen. However, vision systems also use cameras or zoom optics to relay an image to a display. Other accessories such as edge detection, touch probes, other types of sensors, and automation technology can also often be integrated into these systems.

If you're not sure what type of dimensional inspection equipment makes the most sense for your application, working with an expert is best to ensure accurate results. Q-PLUS Labs provides in-house or on-site dimensional measurement services for virtually any industry or application.

What types of objects do you need to measure? Do you think that using a non-contact sensor is the best approach?