Target Material and Characteristics

Transparent/Opaque Targets

There are a number of measurement systems that are capable of measuring a target that is opaque. When it comes to transparent targets, the measurement system being used must match the material of the target being measured. For example, if you’re attempting to measure plastic you should use a contact-type measurement system such as a micrometer. When performing a soft target measurement, such as film, a non-contact measurement system (such as a laser displacement sensor) should be utilized.

Hard/Soft Targets

Objects made out of hard material (such as a block of wood), would require a measurement system that would make direct contact with the target in question (take micrometers and vernier calipers for example). Soft targets on the other hand (such as a water based solvent), can’t be measured in the same manner as a hard based target. This is because connecting directly to a soft based target won’t give you the desired results that you need for a precise measurement. These types of targets require the type of measurement system that’s considered to be “non-contact” such as one that that uses laser beams.

Number of devices and installation costs

One of the factors that should be taken into consideration when selecting a device is the number of people who will be using the device and how frequent the device will be in use. Price and availability should always be one of the top things you consider when you’re shopping for a measurement system.

Large-scale Measurement System Introduction & Particular Processes

Manufacturers who use measurement systems typically include vernier calipers and rules. These devices can be used when measuring units that are 0.1 mm to 1 mm in length and have been used by multiple people as personal-use measurement systems.

Let’s not forget that one of the big uses of measurement systems is for the inspection of manufacturing lines, such as checking the dimension of a mass produced tube. Each target unit will require a range of accuracy requirements thus the measurement system that you plan on using should be specifically selected for the desired accuracy of the job. In most cases the higher the accuracy the more expensive the equipment. As technology evolves more advanced machinery such as 3D measurement systems are becoming more widely available for manufacturers to purchase to speed along their production processes. As a result you have to consider modifying or improving the environment where the measurement system will be installed.

Another common application of capacitive sensors is precision positioning. The position of objects can be measured to the nanometer level. This type of high end positioning and measuring is typically used in the industries that utilize semiconductors where silicon wafers need to be positioned in a specific manner so that they receive the right kind of exposure. Another function of capacitive sensors is pre-focusing electron microscopes used for the examination and testing of the wafers.

Comparison to eddy current displacement sensors

It turns out that capacitive displacement sensors share many things in common with eddy/inductive current displacement sensors. The one defining difference between the two systems is that capacitive sensors use an electric field. Eddy fields, on the other hand, use magnetic fields. Due to this massive difference, these two systems vary greatly from each other. The most notable difference between the two is the fact that capacitive sensors are typically capable of measurements at a higher resolution. Also, eddy current sensors can function perfectly fine in a dirty environment whereas capacitive sensors cannot.