Selection criteria and requirements of sensor or transducer


The following are certain features that are considered when choosing a sensor.

  1. Type of Sensing: The parameter that is being sensed like temperature or pressure.
  2. Operating Principle: The principle of operation of the sensor.
  3. Power Consumption: The power consumed by the sensor will play an important role in defining the total power of the system.
  4. Accuracy: The accuracy of the sensor is a key factor in selecting a sensor.
  5. Environmental Conditions: The conditions in which the sensor is being used will be a factor in choosing the quality of a sensor.
  6. Cost: Depending on the cost of application, a low-cost sensor or high-cost sensor can be used.
  7. Resolution and Range: The smallest value that can be sensed and the limit of measurement are important.
  8. Calibration and Repeatability: Change of values with time and ability to repeat measurements under similar conditions.

Basic Requirements of a Sensor or Transducer
The basic requirements of a sensor are:
  1. Range: It indicates the limits of the input in which it can vary. 
  2. Accuracy: It is the degree of exactness between actual measurement and true value.
  3. Sensitivity: Sensitivity is a relationship between input physical signal and output electrical signal. 
  4. Stability: It is the ability of the sensor to produce the same output for constant input over a period of time.
  5. Repeatability: It is the ability of the sensor to produce the same output for different applications with the same input value.
  6. Response Time: It is the speed of change in output on a stepwise change in input.
  7. Linearity: It is specified in terms of the percentage of nonlinearity. Nonlinearity is an indication of the deviation of the curve of actual measurement from the curve of ideal measurement.
  8. Ruggedness: It is a measure of durability when the sensor is used under extreme operating conditions.
  9. Hysteresis: Hysteresis is a characteristic that a transducer has in being unable to repeat its functionality faithfully when used in the opposite direction of operation.

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