Types of Sensors
You'll be amazed at just how many there are

As sensor technology evolves, there are many types of sensors becoming available. More and more sensors will have a wireless function built in. If not, and if required, you can often add it externally... and easily.

So how many sensor types are there?

Well, depending on how you describe them, there are more than 100... and still counting!

Sometimes we describe a sensor by the basic parameter (or variable) that it’s sensing... such as temperature. At other times we may describe it as an air temperature sensor, or a water temperature sensor, or an engine temperature sensor.

It doesn’t really matter. In this case we are still measuring the same basic parameter - temperature... the important thing is what we are interested in measuring the temperature of... what your application is.

There’s no right or wrong way... it’s a matter of what works... what’s the most convenient... the way that’s easiest to understand.

Below, you’ll see a list of sensor types, listed in alphabetical order. The list is a mix of names, sometimes relating to the basic parameter and sometimes to the application.

Want more information? Click on those shown as a blue link. These will take you to a page with more detail.

Types of sensors in alphabetical order

abs sensor
acceleration - these sensors sense acceleration (a change in velocity) in one, two or three axes (x, y, z) depending on the type.
acoustic - sense changes in air pressure. This is what our ears sense as sound. An example of an acoustic sensor is a microphone.
air bag - these use an acceleration sensor as the trigger. If the sensor detects a rapid rate of deceleration, such as a car hitting a brick wall, the air bag is inflated.
air flow
air mass
air quality - there are many pollutants that lower the quality of our air. Gases such as nitrous oxides, carbon monoxide, carbon dioxide and sulphur dioxide; particulates such as Pm10, Pm 5 and PM 2,5 that can enter our lungs, while transporting harmful chemicals or simply reducing lung volume.
air temperature - for measuring the ambient temperature of the air
alarm motion
ambient light
angle
aps advanced positioning
ascender
automotive oxygen
automotive

barometric pressure sensor - for measuring the weight of air pressing down on the earth's surface. Air is most dense at the Earth's surface and decreases in density with increasing altitude, eventually becoming 'vanishingly thin'.
beam
bed occupancy
biometric- these electronically scan and process characteristics such as fingerprints to provide fast authentication to enable entry to buildings, use of machinery etc.

cam position sensor
capacitance - the capacity to store electric charge
capacitive humidity - used to measure the percentage of water vapour in the air
capacitive proximity - senses when something is getting close by sensing a change in capacitance. This is one of those types of sensors that either gives an output proportional to size of the object approaching and how closely it approaches or switches when it reaches a threshold, for example in a 'non-contact' liquid level sensor..
car parking
car
carbon dioxide (CO2) - for measuring the concentration of carbon dioxide in the air
ccd
chair
chemical - these may present a catalytic surface to the chemical species you want to sense. When that chemical is present, there's a chmical reaction at the surface. This generates an electrical signal that's proportional to the concentration of the chemical.
carbon monoxide (CO) - carbon monoxide concentration in air
conductivity - tells us how well a liquid will conduct electricity
coolant level
coolant temperature
crank angle
crank position
current (electric)

displacement sensor - for sensing changes in position
distance
door
dpfe
driveway motion

engine knock
electrical conductivity (EC)

faucet sensor
fiber optic
fingerprint - these will become more popular as a means to verify personal identity
flame
flow
fluxgate magnetic
force
frequency - the number of times something happens every second, measured in Hertz (a long time ago this was called cycles per second).
fuel flow
fuel level

garage door sensor
garage parking
gas sensor - for measuring the concentration of gases
glass break
glucose - senses the concentration of glucose in blood
gps - global positioning system, senses location on the earth's surface
gyro

hall effect sensor - senses a magnetic field
heat
home security
humidity

inertial sensor
infrared - for sensing invisible Infrared light
ir beam

lambda sensor
laser
light
lightning - detects pulses of the electromagnetic energy generated by discharges. A system of sensors can locate the position of a lightning strike to about a kilometre, though these are usually operated as a service by meteorological organizations. They may even give a value for the electric current (Amperes) that flows and its direction.
linear position
liquid level - can sense the position of the liquid surface from above with an ultrasonic sensor, or have a float coupled to an electronic rotary encoder or a pressure sensor that measures the weight of the water above it.
load - a load cell produces a signal proportional to the weight that's on it.

magnetic proximity
magnetic
map
mass air flow
mems - micro electro mechanical systems, include vibration sensors
microwave motion
moisture - usually measure the amount of moisture on a surface
motion -
movement

natural gas sensor - concentration of the gas in air

oil pressure sensor - can provide an indication of oil pump failure or lack of oil to lubricate moving mechanical parts such as pistons.
oxygen - gaseous (eg. in air) or dissolved oxygen (DO) in water. DO is important to aquatic animals such as fish. Aquatic plants can deplete oxygen from water at night, when they respire, but generate oxygen in sunlight when they photosynthesize.

parking sensor - a sensor activated by a car in a parking building. Useful for flagging which parking spaces are available and which are taken up.
pH - the acidity (hydrogen ion concentration)
photoelectric - light energy is converted to a proportional amount of electric current.
piezoelectric - senses sound or vibration, producing a voltage
pir motion - passive InfraRed, where the heat given off by a person or animal is detected by an InfraRed sensor.
position
pressure - measures the amount of force,such as weight, bearing down on a surface
proximity - how close a thing is to something else

rain - presence, volume and intensity
reed - a switch that can be activated by a magnet and often used in security applications
remote - any sensor that's wirelessly linked to the base station.
rfid - for electronic identification

smart - this is a term used to describe sensors that have processing power. They can be configured, make decisions and adapt to different situations, such as automatically change range to preserve the best resolution possible.
soil moisture - for sensing the water content in a volume of soil.
solar - These sense solar radiation. There are different types, depending on what part of the sun's radiation you want to measure. Some measure direct radiation by 'looking' directly at the sun. Others measure indirect solar radiation, measuring the backscatter or reflection from the atmosphere while shaded from the direct rays. Some measure the full visible spectrum and others measure that part of the visible spectrum that makes plants grow... the part that drives photosynthesis. These are called PAR sensors.
speed
strain - for measuring length change due to applied force
stud

temperature sensor - for measuring temperature of most things
tire pressure - this is one of the types of sensors that will likely be fitted to all vehicles with pressurized tires some day. These tire pressure monitoring systems can send real-time tire pressure information to a display in a vehicle and give early warning if the pressure in any tire is outside its normal range.
torque sensors - for measuring turning force
touch