7 Sensors

Question 1

What does a sensor do?

Answer 1

A sensor produces and electrical signal from its input to its output

Question 2

Name 5 examples of sensors

Answer 2

Temperature
Humidity
Pressure
Airflow
Oxygen

Question 3

What are the 4 sensor characteristics

Answer 3

Accuracy
Calibration Error
Hysteresis
Nonlinearity

Question 4

Define accuracy

Answer 4

Main concern is inaccuracy
Measured as the ratio of the the biggest difference between the sensor’s measured value and the ideal value.

Question 5

Define calibration error

Answer 5

The inaccuracy that is permitted by the manufacturer when the sensor is calibrated
The error is systemic by nature
The error is not necessarily uniform over the range

Question 6

Define hysteresis

Answer 6

The difference between an sensor’s output at a specific point of input signal when approached from different dirtections.
It is the dependence of the state of a system on its history

Question 7

Define nonlinearity

Answer 7

Specified for sensors whose transfer function can be approximated with a straight line.
Is the maximum deviation of a real transfer function for a striaght line.

Question 8

Draw the schematic diagram of a typical sensor

Answer 8

Sensor -> Precision Amplifier -> High Resolution ADC -> Microcontroller -> To interface

Question 9

Name the 4 types of temperature sensor

Answer 9

Thermocouple
Resistence Temperature Detector (RTD)
Thermistor
Semiconductor