Tag: instrumentation and control
-
What is a Microsyn Transducer?
This is a variable-reluctance transducer used to detect small motions, giving output signals as low as 0.01° of changes in angles. The figure below shows an example of Microsyn: In the Microsyn transducer above, the coils are connected in such … Read more
-
Steam-heated Reboiler Control System
When steam-heated reboilers are used in distillation columns and the heating medium is steam, a flow control loop for the steam will typically be incorporated. The control valve can then be placed either in the steam or condensate line. Steam … Read more
-
Furnace Control System for a Rapidly Changing Demand
Let’s consider the figure below: Figure 1.0 Typical single-fuel cross-limited combustion control system In the system above, the output of temperature controller TC represents the process demand, and this signal is applied as one of the inputs, each to a … Read more
-
Industrial Process Temperature Control System
Let’s consider the industrial process control system shown below: Figure 1.1 Industrial Process Temperature Control System The requirement is to control the temperature ϴ in the tank. The voltage r, obtained from a potentiometer, is calibrated in terms of the … Read more
-
How to Perform Mass flow Measurements with DP sensors
Let’s assume we are measuring flow by differential-creating primary device for example an orifice plate and a DP cell as illustrated in Figure 1 below: Figure 1 Liquid mass flow measurement The differential head across the primary device is corrected … Read more
-
Instrumentation and Controls for a Steam Desuperheater
A steam generator is an item of plant equipment that is found in almost every manufacturing site, and its output of steam has many critical uses in a variety of production processes. Steam has been assigned a measurement quality and … Read more
-
The Instrumentation for Furnace Control
The figure below shows a typical basic furnace used to raise the temperature of a heat-transfer medium that is used on other equipment in a plant process. Figure: Single-fuel combustion control system From the figure above, the temperature of the … Read more
-
Null vs. Deflection Type Instruments
Null Instrument The null technique is one of the operational modes for a measuring instrument. A null instrument employs the null method for measurement. In this technique, the instrument exerts an influence on the measured system so as to oppose … Read more
-
Analog vs. Digital Sensors
Analog Sensors Analog sensors provide a signal that is continuous in both its magnitude and its temporal (time) or spatial (space) content. Most physical variables such as, current, pressure, temperature, displacement, acceleration, speed, light intensity and strain tend to be … Read more
-
What are PLC-Based Water Treatment Plants?
Most of the water treatment plants in the previous decade were manually operated. However, they were automated to a certain degree using relays or electrical control panels but the system was not reliable and required a lot of space. In … Read more