When searching for an LVDT Linear Position Sensor for an application, you or your design engineer often must decipher a multitude of product specifications to configure the right sensor.
Below are tips on how to take a step-by-step approach in sorting through all the information to specify the right displacement sensor that matches your requirements.
1. What is the measuring range? Sensors are designed for work over certain measurements ranges. LVDTs are best suited to make measurements from roughly ±0.010 inches to ±10 inches. Granted, a few special cases exist outside that range, but the vast majority are within that range.
2. What is the application? Understanding the broad application can go a long way in narrowing down the best LVDT. For example, if you are looking to make quality measurement checks on an assembly line using an automated system or where the movement is not perfectly linear and some side-to-side motion can exist, a spring-loaded LVDT could be a good choice. For a linear valve position measurement, a separate-core LVDT could be the best choice. To understand the difference in technology, refer to: http://www.macrosensors.com/position_sensor_selection_guide.html
3. Are there space restrictions? Sometimes, your application has a limited amount of space in a fixture for an LVDT. If space is a concern, smaller LVDTs, such as Macro Sensors Miniature 3/8″ LVDTs, can fit into tight places.
4. What are the environmental considerations? If heavy dust, dirt, humidity or jetting are present, or if the sensor will be installed outdoors, a hermetically-sealed LVDT is probably the best choice. In a more benign or indoor laboratory environment, a standard non-hermetically sealed unit will get the job done with a lower up-front cost. For in-cylinder applications with hydraulic fluid, a “vented” LVDT will perform well. Special configurations of LVDTs also exist that offer mild resistance to radiation and operation when submerged underwater or in high pressures or atmospheric conditions.
5. What is the operating temperature? A DC-operated LVDT can be used at temperatures at or below 85°C. If higher, AC-operated LVDTs can handle temperatures up to 200°C and even higher with remote signal conditioning electronics operating outside the unit in an environmentally controlled area.