Byte-sized Topic: Industrial Sensors
April 20, 2017
Industrial sensors are the eyes and fingers of the factory control systems. They provide feedback to the control system about what is the situation in the production process:
Is a bottle ready for filling ?
How many bottles have been produced today?
Is the batch of metallic parts already in the painting line?
They usually connect to an automation system (PLC, DCS, etc.), via remote I/O (input/output) devices. The automation system, then, uses this information to take decision on what to do next, depending upon what tasks the system has programmed to execute.
To make it easy, let’s image the system in the factory as a human body, where each of its components plays a specific role in letting signals flow from the top (brain) to the tip (finger) and communicate the result back to the top (from the finger… back to the brain). See here below a graph with a breakdown of this process.
Furthermore, many different industrial sensors can be found within factories and on the market. They are of many types, shapes, materials, and characteristics such as:
- Proximity Inductive
- Proximity Capacitive
- Limit switch
- Round with screw
- Round without screw
- Plastic (polycarbonate, ABS, etc.)
- Metallic (stainless SUS 304, SUS316)
- Composite (PTFE/Teflon, etc.)
- Sensing distance (how far can the sensed object?), in mm.
- Type of sensing (for metallic objects, for plastic, transparent or non-transparent, etc.)
Major manufacturers of industrial sensors are:
- Schneider Electric
To put in context the graph outlined above, here below is an example of a large automation infrastructure in a process factory (e.g. Oil refinery).