Instrumentation

More Information about Instrumentation

Limit switches are electromechanical devices that detect the presence or absence of an object or determine its position. Commonly used in machinery and industrial equipment, they act as safety devices to prevent machinery from moving beyond a predetermined point, thus ensuring operational safety and preventing equipment damage.

Temperature sensors are crucial in almost every industrial process. Devices like thermocouples, resistance temperature detectors (RTDs), and infrared sensors provide accurate temperature readings, which are essential for process control, quality assurance, and safety. They find applications in industries such as food processing, pharmaceuticals, and automotive manufacturing.

Pressure sensors are used to measure the pressure of gases or liquids in a system and are critical in applications where pressure needs to be monitored or controlled. These sensors can be found in HVAC systems, hydraulic systems, and in the monitoring of environmental conditions. They come in various types, including piezoelectric, strain gauge, and capacitive pressure sensors, each offering different ranges and sensitivities.

Analog and Digital Control Signals: The Basics

Digital Signals

Digital signals are represented in either a true or false. There is no gray area with digital signals. An example of this might be a light switch. A light switch is either on or off. Another example of this might be a motor that is running or not running. Digital signals can be generated with both AC and DC circuits with varying voltages, currents and resistance. Some practical examples of using digital signals in an industrial environment might be if a pump is running or not running or a whether a valve is open or closed.

Analog Signals

Analog signals convey information in the form of a range. A light switch might be on or off as a digital signal, but a dimmer switch would be an analog signal. It can be on or off, but it can also be somewhere in between. A practical example of using analog signals in an industrial environment would be if there is a need to measure the level of a tank; whether it's full, empty or somewhere in between. Analog signals can take many different forms with some of the more common being a 4 to 20 milliamp signal or a 0 to 5 or 0 to 10 volt signal. 

Communication

Communication in a device can either be sent or received. Whether that data is sent or received depends on the type of information. Is there a need to monitor the status of something? If so, an input needs to be received about that information. Is there a need to control something? If so, an output needs to be sent about what needs to occur. Receiving inputs and setting outputs are both things that can be accomplished by using both digital and analog signal types. Therefore, the signals are referred to as analog outputs (AO), analog inputs (AI), digital inputs (DI) or digital outputs (DO).