Tag: instrumentation and control
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Safety Function in a Machine Control System
A safety function is executed by the safety-related parts of the machine control system to achieve or maintain the equipment under control in a safe state with respect to a specific hazard. A failure of the safety function can result … Read more
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Types of Load Cells and How Do They Work?
In the vast landscape of industrial measurement, load cells play a pivotal role in ensuring the accuracy and reliability of weight and force measurements. These sophisticated devices, integral to myriad applications across industries, convert mechanical force into measurable electrical outputs.… Read more
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Combustion & Temperature Control for a Direct-Fired Process Heater
The figure below shows the control schemes applied to a direct-fired process heater. Fig: Combustion & temperature control on direct-fired process heater From the diagram above, the heat from the burning fuel is applied directly to the tubes carrying the … Read more
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What are Control and Instrumentation Cables?
While power cables are what we can refer to the “arteries” of industry, control and instrumentation cables are its “nerves” and are used for the control of equipment and data collection. They range from switch-core cables utilized in the wiring … Read more
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How Synchros are used as Position Transducers
Let’s consider the transformer in Figure 1.0 whose secondary winding can be rotated with the respect to the primary winding. Figure 1.0 Synchro torque transmitter At an angle ϴ, the output voltage will be given by: Vo = KV… Read more
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Actuators as Automation Components
An actuator is normally controlled by the controller. The actuator, in turn, changes the output of an automated process. The actuator in an automated process may in actual fact be several actuators, each of which provides an output that … Read more
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The General Principle of using a Servo Motor for Position Control
Servo motors are typically employed in closed-loop position control; for example let us consider the following application, where the angular position of the output shaft is intended to follow the reference voltage (ϴref). Figure 1.0 Closed loop angular … Read more
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Designing a System to Measure & Display a Shaft Rotation Speed
We would like to design a system to measure and display the rotational speed of a shaft. To accomplish this, we shall use a number of integrated circuits (ICs) to create the desired functionality of this system. A simple technique … Read more
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Analog vs. Digital Controllers
Analog signals pass continuously through a full range of values for example a measuring device converts the process variable (PV), say temperature, into a signal corresponding to this temperature. Each temperature value corresponds to a value of the electrical signal. … Read more