Basic knowledge of sensors and common terms

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Basic Knowledge and Common Terms of Sensors 1. Sensor: A device or apparatus that can detect a specified quantity to be measured and convert it into an usable output signal according to certain rules. It usually consists of sensitive elements and conversion elements. (1) A sensitive element refers to the part of a sensor that can directly (or respond to) the quantity being measured. (2) A conversion element refers to the part of a sensor that converts the quantity to be measured, which can be sensed (or responded to) by more sensitive elements, into an electrical signal suitable for transmission and/or measurement. (3) When the output is a specified standard signal, it is called a transmitter. 2. Measurement range: The range of the measured value within the allowable error limit. 3. Range: The algebraic difference between the upper and lower limits of the measurement range. 4. Accuracy: The degree of consistency between the measured value and the true value. 5. Repeatability: The degree of consistency among the results obtained from multiple consecutive measurements of the same quantity under all the following conditions ； Repetition within a short period of time, using the same measurement method, the same observer, the same measuring instrument, the same location, and the same operating conditions. 6. Resolution: The smallest change in the quantity being measured that can be detected by the sensor within its specified measurement range. 7. Threshold: It is the minimum change in the measured quantity that can cause a measurable change at the sensor’s output. 8. Zero position: The state in which the absolute value of the output is minimized, such as the balanced state. 9. Excitation: The external energy (voltage or current) applied to enable the sensor to function properly. 10. Maximum excitation: The maximum value of the excitation voltage or current that can be applied to the sensor under indoor conditions. 11. Input impedance: The impedance measured at the sensor’s input terminal when the output is short-circuited. 12. Output: An electrical quantity generated by a sensor that is in a functional relationship with the external quantity being measured. 13. Output impedance: The impedance measured at the sensor’s input terminal when the input is short-circuited. 14. Zero-point output: The output of the sensor under indoor conditions when the applied measured value is zero. 15. Hysteresis: Within the specified range, the maximum difference that appears in the output as the measured value increases and decreases. 16. Delay: The time delay between the change in the output signal and the change in the input signal. 17. Drift: Over a certain time interval, the sensor output eventually experiences unwanted changes that are unrelated to the measurement. 18. Zero drift: The variation in the zero output over specified time intervals under indoor conditions. 19. Sensitivity: The ratio of the increase in the sensor’s output to the corresponding increase in the input. 20. Sensitivity drift: Change in the slope of the calibration curve caused by variations in sensitivity. 21. Thermal sensitivity drift: Drift in sensitivity caused by changes in sensitivity. 22. Thermal zero-point drift: Zero-point drift caused by changes in the surrounding temperature. 23. Linearity: The degree to which the calibration curve conforms to a specified standard. 24. Non-linearity: The degree of deviation of the calibration curve from a specified straight line. 25. Long-term stability: The ability of the sensor to maintain an error within the allowable limits over a specified period of time. 26. Natural frequency: The free (without external forces) oscillation frequency of the sensor in the absence of resistance. 27. Response: The output is a characteristic of the change in the quantity being measured. 28. Compensation temperature range: The temperature range for which compensation is applied to maintain the sensor in zero balance within its range and specified limits. 29. Creep: The change in the output over a specified period of time when the environmental conditions surrounding the machine being measured remain constant. 30. Insulation resistance: Unless otherwise specified, it refers to the resistance value measured between the specified insulated parts of the sensor when a specified direct current voltage is applied at room temperature.