Thermocouples
Resistor temperature detectors (RTD)
Resistor temperature detectors (RTD)
IC (Semiconductor)
Infrared sensors

Proximity sensor

A device that detects the presence or absence of a nearby object, or properties of that object, and converts it into signal which can be easily read by user or a simple electronic instrument without getting in contact with them.

Inductive Sensors: Inductive proximity sensors are used for non-contact detection to find out the presence of metallic objects using electromagnetic field or a beam of electromagnetic radiation.It

Capacitive Sensors: Capacitive proximity sensors can detect both metallic as well as non-metallic targets. Nearly all other materials are dielectric different from air. 

Photoelectric Sensors: Photoelectric sensor is made up of light-sensitive parts and uses a beam of light to detect the presence or absence of an object. 

Ultrasonic Sensors: Ultrasonic sensors are also used to detect the presence or to measure the distance of targets similar to radar or sonar. This makes a reliable solution for harsh and demanding conditions.

Pressure sensor

A pressure sensor is a device that senses pressure and converts it into an electric signal.

Water quality sensor

Water quality sensors are used to detect the water quality and Ion monitoring primarily in water distribution systems.

Following is a list of the most common kind of water sensors in use:

Chlorine Residual Sensor: It measures chlorine residual (i.e. free chlorine, monochloramine & total chlorine) in water and most widely used as disinfectant because of its efficiency.

Total Organic Carbon Sensor: TOC sensor is used to measure organic element in water.

Turbidity Sensor: Turbidity sensors measure suspended solids in water, typically it is used in river and stream gaging, wastewater and effluent measurement.

Conductivity Sensor: Conductivity measurements are carried out in industrial processes primarily to obtain information on total ionic concentrations (i.e. dissolved compounds) in water solutions.

pH Sensor: It is used to measure the pH level in the dissolved water, which indicates how acidic or basic (alkaline) it is.

Oxygen-Reduction Potential Sensor: The ORP measurement provides insights into the level of oxidation/reduction reactions occurring in the solution.

Following are most common kind of chemical sensors in use:

Chemical field-effect transistor

Chemiresistor

Electrochemical gas sensor

Fluorescent chloride sensor

Hydrogen sulfide sensor

Nondispersive infrared sensor

pH glass electrode

Potentiometric sensor

Zinc oxide nanorod sensor

Following are some common Gas sensors:

Carbon dioxide sensor

Breathalyzer

Carbon monoxide detector

Catalytic bead sensor

Hydrogen sensor

Air pollution sensor

Nitrogen oxide sensor

Oxygen sensor

Ozone monitor

Electrochemical gas sensor

Gas detector

Hygrometer

Common Type of Smoke Sensors

Smoke sensors detect the presence of Smoke, Gases and Flame surrounding their field. It can be detected either optically or by the physical process or by the use of both the methods.

Optical smoke sensor (Photoelectric): Optical smoke sensor used the light scatter principle trigger to occupants.

Ionization smoke sensor: Ionization smoke sensor works on the principle of ionization, kind of chemistry to detect molecules causing a trigger alarm.

IR sensors

An infrared sensor is a sensor which is used to sense certain characteristics of its surroundings by either emitting or detecting infrared radiation. It is also capable of measuring the heat being emitted by the objects.

Level sensors

A sensor which is used to determine the level or amount of fluids, liquids or other substances that flow in an open or closed system is called Level sensor.

There are two basic level measurement types:

Point level sensors: Point level sensors usually detect the particular specific level and respond to the user if the sensing object is above or below that level. It is integrated into single device to get an alarm or trigger

Continuous level Sensor: Continuous level sensors measure liquid or dry material levels within a specified range and provide outputs which continuously indicate the level.

Image sensors

Image sensors are instruments which are used to convert optical images into electronic signals for displaying or storing files electronically.

Two main types of sensors are used in:

CCD (charge-coupled device), and

CMOS (complementary metal-oxide semiconductor) imagers.

Motion detection sensors

A motion detector is an electronic device which is used to detect the physical movement (motion) in a given