Instrumentation and control: leveraging efficiency

November 17, 2014 3:46 pm

Instruments play a vital role in all processes in industry. The field of instrumentation and control is experiencing some of the exciting innovations nowadays
Instrumentation is usually known as the art and science of measurement and control of process variables within a production or manufacturing area. The process variables used in industries are level, pressure, temperature, humidity, flow, ph, force, speed etc.
When it comes to control operation, the practice uses sensors to measure the output performance of the device being controlled and those measurements can be used to give feedback to the input actuators that can make corrections toward desired performance. When a device is designed to perform without the need of human inputs for correction it is called automatic control (such as cruise control for regulating a car’s speed).
Instrumentation and its importance Over the period, it is observed that instruments actually play a vital role in all processes in industry. In almost all applications, their importance is already established. By controlling right from the specifications of the raw materials to the process parameters, a low cost low rejection – prone product may be easily produced.
“For cost-effective way of using process control and instrumentation, certain basic facts should be understood and then the refinement in the process technique may be applied,” says Vishwas Kale, Managing Director, Vijayesh Instruments Pvt. Ltd. “Saving energy is important for environment as well as for cost control. To manage saving of energy, we should have answers for this. What is to be measured, controlled and recorded/ logged? And also ‘why’ for every item.”
Instruments also help in monitoring the process accurately and safely.  Now the process can be monitored effectively from single location (control room) by using proper sensors and instruments.
Sanjay Belhe, Director – Marketing, Protocontrol Instruments (I) Pvt. Ltd. says, “In any automated process, sensors play role of eyes and ears while instruments play role of brain. No process can be automated without use of sensors and instruments.” Major aspectsIn measurement industry, one cannot control what cannot be measured. Sensors are the foundation of feedback control. Sensors measure the process variable and transmit a signal that represents the measurement to the controller. The quality of performance of the system is directly related to the performance of the sensor.
The process variables which are being measured are mostly temperature, pressure, level, flow and mass. No sensor measures a process variable directly. Each sensor measures the effect of the process variable by physical position, force, voltage or some other more easily measured property.
Instrumentation is the basic process control in the industry. In industrial control number of variables like temperature, flow, level, pressure, and distance can be sensed simultaneously. All of these can be interdependent variables in a single processing require a complex microprocessor system for total control. Due to more advancement in technology and the efficient measurement techniques instruments that we are using today may be obsolete in future. Hence choosing appropriate instrumentation technique becomes obviously essential.
During specifying the instrumentation, the main objectives of the designer should be:• Safe plant operation• High production rate• Low production cost• To maintain the product composition within the specified quality limits.
Key functional areasInstrumentation and control finds its applications in variety of areas. Some of the main functional areas include process automation, conveyor protection, and level management.
In practice, instruments have a wide area of functions. A simple Instrument such as programmable logic controller (PLC) has tremendous capabilities. This small gadget includes many features, which may otherwise require several individual units to achieve. This will mean lower installation wiring and commissioning costs as well as simpler operator interface. Such features include: any calibration is possible on shop floor (e.g. temperature, pressure, flue gas etc.) accurate programmer control, advanced self tuning strategies, real time clock, timer, totalises, programmable logic and mathematics functions and flexible integration. Thus a PLC may be used at any place in the plant by just readjusting its user friendly features. Latest innovationsAs they say – change is the only constant thing, every segment inthe industry keeps changing itself with the help of ever-up grading technology and wonderful advancements. Technology in turn gives rise to new innovations to take place and of course, to benefit the end users. Let us find out what are the latest innovations are happening in the field of industrial instrumentation and process control. “We introduced an innovative product Trip Indicator after extensive research of 8 years,” informs Mr Belhe. “This product has changed the scenario of conveyor protection in CHP (Coal Handling Plant) and RMHS (Raw Material Handling Systems) areas.”
“The techniques of instrumentation are getting updated continuously,” says Mr Kale. “Laser operated sensors to align production materials, gas sensors to detect even low concentrations, moisture sensors for agriculture use etc. to name a just few.”
The metal industry uses automation in aluminium die casting, steel making and remote radio control in heat treatment. Food and pharmacy industry have specific compatible and very critical meeting controllers, suitable to work in those environments. For transporting medicines, perishable items etc., data loggers with memory are put with the load and they monitor and record the controlled temperature and humidity conditions in the travelling vehicle. Portable spectrometers, non-contact infra red thermometers, which can be carried on the shop floor for on the spot analysis, are now commonly used.
Current offeringsIt is now interesting to see what are the solutions current industry players have to offer in market to meet the ever-changing needs for various applications. Today companies have specific key offerings in industrial instrumentation and process control. Let us explore the same.
Protocontrol is today one of the leading suppliers of sensors and control instruments for temperature, level, pressure and speed monitoring. Its safety switches play major role for protection of conveyor belts used in power plants, steel plants and cement plants.
Its Trip Indicator comes in two different models as: Trip Indicator (TRA) and Trip Indicator (TRS).
In fact, there is wide need for calibration of almost all parameters measuring sensors and instruments. For this, calibrators, testing units with valid certifications are now being made. Testing units for automobiles, such as testing of flammability, distortion, cable harness, fuel tanks etc. are also now being made.
“We continuously monitor the needs and offer options. Some of the instruments which are not made in India are substituted with equivalent units by indigenous technology. Rare gas purifiers, process thermocouples with SAT facility, furnace mapping units are some examples,” says Mr Kale.
Protocontrol has its other major offerings as follows:• Safety switches• Control instruments• Accessories• Pullcord trip indication system• Level sensing products• Junction boxes• Push button stations
The days ahead will require many innovations in instrumentation and the current picture is looking quite promising as the manufactures are very much confident to meet the increasing market needs.