Environmental monitoring is required for protecting the public and the environment from pathogens and toxic contaminants and is used to prepare environmental impact assessments, as well as establish the circumstances in which human activities risk harmful effects on the natural environment. Different types of monitoring are carried out, including that of air, water and soil. Such monitoring programmes and strategies have justifications and reasons which help them establish the status of an environment or trends in environmental parameters.
There are different types of sensors used for different contaminants and for different degrees of the same. These are discussed below in detail.
Types of Sensors
There are several types of sensors employed, depending on the specifications required for monitoring. Size, speed and sensitivity are all key factors to consider while choosing an environmental sensor. Sensors can be differentiated into different categories depending on the type of sensors being used, and the ecological factors an analyst is looking at.
The main types of sensors include:
Trace Metal Sensors
These include laser-induced breakdown spectroscopy (LIBS), miniature chemical flow-probe and nanoelectrode array sensor.
Radioisotopic sensors include Radiation field-effect transistor (RadFET), low-energy pin diodes beta spectrometer, cadmium zinc telluride (CZT) detectors, thermoluminescent dosimeter (TLD), neutron generator for nuclear material detection, isotope identification gamma detector, non-Sandia radiation detectors etc.
Volatile Organic Compound Sensors
Grating light reflection spectroscopy (GLRS), miniature chemical flow probe sensor, evanescent fibre-optic chemical sensor, chemical sensor arrays, gas-phase MicroChemLab, electrical impedance of tethered lipid bilayers on planar electrodes, gold nanoparticle chemiresistors, hyperspectral imaging, chemiresistor array and MicroHound sensors are all examples of volatile organic compound sensors.
Insulator-based dielectrophoresis, fatty acid methyl esters (FAME) analyser, biological sensor arrays, liquid phase MicroChemLab, μProLab are examples of biosensors.
Sensors can also be split into different types depending on environmental factors.
Moisture sensors are used for the measurement of the quantity of water content in the soil to assess the chimerical environment in several orders of magnitude.
Pressure sensors operate based on the amount of pressure applied to them. They are used in industries such as aviation, automobile and hydraulic measurements and manufacturing biomedical measurements.
The tilt sensor relates the two different axes against a reference plane which may be in two different axes. This is an essential tool for measuring tilt angles with respect to the Earth’s ground plane. Tilt sensors are most commonly used in industry and in-game controllers.
Rain sensors are simple switching devices that get activated in the event of rainfall. Rain sensors are used in water conservation devices in irrigation systems, and sometimes even in automobiles with windscreen wipers.
Vibration sensors are crucial for acceleration and displacement with respect to the lasting impact on the environment. Displacement, velocity and acceleration are different factors that vibration sensors measure accordingly.