Instrumentation is the term used to refer both single instrument and a collective of instruments.
The single instrument may perform physical quantity detection, measurement, analyzing and even magnification. This single instrument can work together with other instruments to perform a particular task; without being connected using a communication line.
On the other hand, a collective of instruments can be networked to process or control or even automate a certain or several tasks. This model shapes a called instrumentation system. They are connected, communicate with each other, and a particular instrument’s task depending on the other instruments.
From simple direct reading thermometers to rocket instrumentation, these instruments can present anywhere.
So, What is Instrumentation?
Instrumentation is a branch of science that take advantage of scientific finding to engineer an instrument that is able to process a particular physical quantity to be convertable, detectable, measurable, analyzable, observed, visible, and even magnified.
As said, the purpose of processing this particular quantity can vary.
A certain instrument is designed for measurement; it processes the physical quantity to be measurable. Some instruments have the purpose to detect only. To observe our skeleton, we use an x-ray machine. The optical instrument makes small organisms or distant objects to be visible.
And even, it turns to another something useful. When you build an automatic open door, the laser actually detects length (physical quantity). If you are near the door, the door will open itself. This instrument detects a certain input and controls a certain output.
Instrumentation can be a single instrument and several integrated instruments.
1. Single Instrument
A single instrument device consists of several elements: input, processing, and output element.
- The input element can be the sensor or transducer.
- The processing element can be a microcontroller or microprocessor depending on the task. In this element, one of its jobs is signal conditioning. Thus, you can find ADC (Analog to Digital Converter) and DAC (Digital to Analog Converter). However, some sensor modules can have the ADC built-in. Hall effect sensor has its signal conditioning integrated within its sensor.
- The output element can be a display, valve, speaker (sound/alarm), motor, etc.
The sensor converts a particular physical quantity into another physical quantity (current, voltage, frequency, etc). Then it turns that electrical signal into a digital signal. Afterward, it processes the digital signal in the processing element (microcontroller) and turns it into a signal understood by the display or another output. Finally, you can consume the result in the way that you want.
Sensor, microcontroller, display, and other output/control elements have to communicate and work together. An instrument engineer needs to establish the appropriate communication protocol so that they communicate as desire. You can choose whether a wired or wireless interface between the input and processor as well as the processor and output.
Aside from that, an instrument engineer has to know what the best sensor is to use when designing a certain instrument. The reason is different applications may require different accuracy levels.
Programming the microcontroller is another important part of the instrumentation.
In instrumentation, an electronic engineer can take part. For example, an electronic engineer could design an effective electronic circuit that consumes less power. Perhaps, you have heard about the Geiger counter that can last for 10 years. By means of this, the measuring instrument can last longer and ready to carry outdoor.
1. Electronic Instruments
An electronic instrument means an instrument that uses electrical power to operate. It can also refer to electrical instruments. Almost all the elements make use of electricity.
Almost every instrument today has been constructed electronically to make them more portable and affordable. For example, digital tape measures such as eTape16 tape measure, digital thermometers, home wheater station, paint thickness gauge, digital watches, and many more.
2. Mechanical Instruments
Compass and sun watch are some of the simplest mechanical instruments. By applying the phenomenon of a magnetic needle that always shows north direction, you could use it as an instrument for navigation.
Today’s non-electronic instrument models are still reliable to use such as vernier caliper, dial caliper, dial indicator, and dial test indicator. They don’t need electrical power to operate while giving you a satisfactory measurement.
Since it doesn’t use electrical power, the display is mechanical too. Therefore, you can find them come with a dial scale, mechanical counter, needle, colored indicator, etc.
When designing a mechanical instrument, a strong knowledge of mechanical principles is necessary. For example, making a retractable good tape measure requires a good metallic material. A tape measure uses a spring mechanism to work. This material, when it’s coiled, needs to maintain its physical property. Otherwise, the retractable tape will lose over time.
Perhaps, it’s not crucial. However, when it comes to the dial indicators or test indicators, they can impact precision if the coiled spring or hairspring is not made from good material.
Other examples of mechanical instruments are automatic watches, balance scales, direct reading thermometers, retractable tape measures, rulers, propane tank pressure gauge, magnetic paint thickness gauge, etc.
This one-purpose single instrument is easy to find in electronic test labs, medical equipment, analytical measurement, etc.
In the electronic test laboratory, we will find microscopes, oscilloscopes, spectrum analyzers, logic analyzers, capacitance meters, benchtop multimeters, and many more as instruments.
You will find the telescope as one of the astronomical instruments.
Biomedical instrumentation can be dental loupe, x-ray machine, sonogram, stethoscope, thermometer, and many more.
Speedometer, tachometer, oil-pressure and water-temperature gauge, voltmeter, airbag sensor, and hour meter are some instruments you can find in your vehicle (automotive instrumentation). Currently, lidar is used to build an autonomous vehicle.
GPS, altimeter, compass, etc are important parts of aircraft navigation.
You can set up your own weather instruments such as an anemometer, thermometer, psychrometer, barometer, hygrometer, etc.
An alarm system can be instrumentation as well. It may detect movement, light, etc and release the output such as sound or video capture, etc. Aside from that, you can install a hidden camera as your home security instrument.
2. A Collective of Instruments
Instrumentation and control can refer to a collective of instruments that are connected and form a system to process, control, and even automate a certain or several jobs. The control element can be fully-, semi-controlled and human-controlled. You can find this in the manufacturing process, power plant, wastewater treatment, etc.
A particular instrument keeps detecting a particular physical quantity. It keeps transmitting the data to the microcontroller or the advanced one (PLC). At a particular level of measurement, it will send a command to the output element. Then the output element will control that physical quantity.
In the process plant, they can be an automated process. The instruments must be in high repeatability. This repeatability is important to produce the same quality products.
An instrumentation engineer must design an effective instrumentation system that saves effort, time, and money. They must have the ability to design the diagram, detail, maintain, calibrate, and trouble shoot. When it comes to calibration, the instrument engineer may need to work with a metrologist to maintain the accuracy and precision of the instruments and devices.
Moreover, the field of electrical engineering can be very helpful when building an instrumentation system as it requires electrical power and other electrical circuits. Therefore, the instrumentation engineer needs to work with an electrical engineer.
Job Description in Instrumentation
The instrumentation engineer will design the system. The engineer has to integrate the sensors to the microcontroller, microcontroller to the control system and display, establish the transmitting line, etc. Aside from that, the engineer has to design the diagram for the system so that the technician can execute the diagram.
When it comes to installation, testing, operation, inspection, calibration, repairment, and maintainance of the instruments in the system, an instrumentation technician is required.
To move further, the instrumentation technologists is needed to research and find a new technology to be implemented in the system. At least, they should be always updated to every new invented (instrumentation) technology.