In my previous blog post we covered the Anatomy of a High Pressure Proximity Sensor. That post covered the different mechanical housing designs and special properties that go into high pressure sensor products with discrete outputs. That is great information to know when specifying the correct sensor for a particular application. In today’s competitive market and constant goals to improve processes, sensor’s that offer continuous feedback are required.
Hydraulic systems regulate speed of an actuator by regulating flow rate. The flow rate determines the speed of the cylinder spud that actuates inside the system. For example, an analog sensor can provide measurement to the controls with indication of slowing down or speeding up the actuator based on the analog feedback from the sensor in regard to position of the tapered section of the actuator. So, if the internal target gets larger with more position movement (stroke) the distant measurement changes and indicates that the end of stroke is near causing the controller to initiate a soft stop. This provides better control of the system offering a more efficient reliable process.
Analog Inductive sensors provide an absolute voltage or current signal change proportional to the distance of a ferrous target. In high pressure applications that require more position feedback, an analog distance sensor can offer a solution as they also offer high – strength stainless steel housings with special sealing designs that allow pressure up to 500 bar and 85°C temperature ratings making them an ideal solution for valve speed control and soft starts with a non – contact design.
More information on high pressure analog inductive sensors is available on the Balluff website at www.balluff.us.
Some industrial applications will require a sensor with special properties. This type of sensor offering is needed especially when pressure comes to play. In a wide range of hydraulic cylinder and valve applications high pressure sensors are exposed to hostile environments and are subject to pressure that a standard sensor simply cannot hold up in. For example 350 bar of pressure can be detrimental to a standard sensor as it is not designed for a pressure application.
High pressure inductive sensors are designed to withstand the severe duty of a high pressure application with product features like corrosion – resistant housing materials, high strength ceramic sensing faces and special sealing techniques such as undercut housings with sealing and support rings. This is very important because not only do we need to have a sensor that can withstand pressure on the face of the sensor without damage we also need to make sure we can keep the hydraulic fluid inside the cylinder or valve where it belongs.
In the photo below you will notice the undercut area at the sensing face of the sensor along with an O-ring and supporting backing ring to make sure the application is sealed tight.
There are several common sizes for different types of cylinder and valves however the same principle applies. Below is an example of a flange mount style offering. This type of sensor takes a different design approach that is bolted to the top side of a cylinder with a sealing O-ring under the mounting point.
It’s also important to know what form factor is needed when specifying a high pressure inductive sensor. Typically you will see pressure options from 50 up to 500 bar. The dimensions of the cylinder or valve will determine what type of high pressure sensor is needed.
To learn more visit www.balluff.us.