When selecting a thickness gauge for your application, there are a number of criteria to consider. Here, we review seven key questions to help you make the right decision for your thickness gauging needs. If you have any questions, you can contact us at info@gauging.com.
It is critical to chose a technology which will work well for your material, and there is not one clear technology that works best for every application.
For example, capacitance technologies that SolveTech offers are not able to process conductive materials such as metals or liquids. Capacitance is commonly used in non conductive applications like the plastic film industry.
Operating conditions may play a role in the technology that is used. For example, very hot environments can affect gauge performance. If the gauge can not tolerate dirt or dust, that may also be an import consideration.
When you are trying to measure the thickness of your material, you may be trying to meet a certain variability specification. Knowing this specification is a good guide for making sure the technology you have selected fits your needs.
Different technologies will offer different resolutions on the material thickness, and accuracy is often dependent on the average material thickness. For example, SolveTech typically has a resolution for our laboratory capacitance gauging systems of 0.1%, but this can be application dependent. Since there are percentages at work, for a 1 mil material, we can measure to 0.001 mils, but we are not capable of measure to 0.001 mils for a 100 mil material.
Also, when measuring a very thin material, the gauge design may change versus a thick material. In a nuclear gauge, you may have to select a different nuclear source to make it through a thin material versus a thick material.
It is very important that the measurement device you use be reliable and repeatable (https://en.wikipedia.org/wiki/Repeatability) .
For our PR2000 system for example, we will run a material and then repeat the same run. We then overlay the graphs of the two runs. If the measurement is repeatable, the graphs should match. (For an example check out the second video on this page https://gauging.com/precision-profilertm/)
A reliable measurement is one that is easily reproducible. This means that if two people take the measurements, they get the same answer. An example of where it would be difficult to get a reliable measurement would be using a caliper to measure a thin film. A good gauging system is designed so that it is easy for the operator to execute a good run technique, which is why in some applications a non contacting method is beneficial.
For more information regarding gauge reliability and repeatability, you can click this link.
http://www.qualitydigest.com/inside/metrology-article/basics-gauge-rr.html
https://en.wikipedia.org/wiki/ANOVA_gauge_R%26R
Testing will often provide the answers to many of the questions asked on this page. It allows the customer to see the technology first hand, and also allows the gauging company to address any unanticipated issues. It is a great way for the buyer to compare technologies and verify the claims of the manufacturer.
SolveTech tests every customer application whenever possible, and it is a necessity when it comes to looking at a new application. We can sometimes determine the viability of a on line unit using a lab unit. We will often run samples in our lab on our PR2000 before declaring the technology compatible.
Durability is a big consideration for many customers. Often, the environment can be dusty, have big changes in temperature, and have operators who are less than delicate on the equipment. There should be design features to handle the conditions on or off the production line.
Contact gauging is commonly used in many applications. Often, a simple pair of micrometers are used. They are able to achieve fairly high accuracy, but do have some limitations.
Non contacting gauges can be great for on line applications since they do not touch the material and can respond to changes in the material quickly. They can also measure thin materials very well when contacting gauges may not have the necessary resolution.
With SolveTech’s capacitance technology, there are no environmental hazards, but with nuclear and X-ray technologies, there may be some environmental issues to consider. You may have to check federal and local rules regarding the material if you have an X-ray or nuclear source. With these sources, there can also be disposal fees to consider. In some applications, these technologies are a necessity, so you will just need to plan accordingly.
Now that you have considered these seven questions, you are ready to make a smart gauging technology decision! If you have any questions, please feel free to contact the gauging experts at SolveTech at info@gauging.com or 302-798-5400.
Selecting a Thickness Gauge | Buy a Plastic Film Gauge| Measure Plastic Film Thickness