When first contacting or using displacement sensors, many friends don't understand some professional terms or parameters of displacement sensors. Then this article will specifically explain the professional terms and some parameter issues of displacement sensors in an easy-to-understand way.

Absolute position output:

The output of the displacement sensor is the position relative to an absolute (fixed) reference point. When the sensor is powered off and then restored to power, there is no need for reset. Unlike general incremental displacement sensors (such as incremental encoders, incremental grating rulers), after power off, a system reset is required to continue measurement.

Nonlinearity:

Along the measurement stroke of the displacement sensor, the difference between the displayed position value of the position magnet and the ideal value. In magnetostrictive displacement sensors, this change is caused by the nonlinearity of signal propagation in the waveguide medium. Nonlinearity is usually expressed as absolute error or a percentage of the effective stroke length.

Repeatability:

When measuring along the stroke, when the magnet repeatedly reaches the same position from the same direction, the difference in sensor output.

Non-contact measurement:

Magnetostrictive displacement sensors and LVDT displacement sensors all adopt the non-contact magnetic induction measurement working principle. Therefore, there is no mechanical wear problem during the entire life cycle of the product. At the same time, this measurement method can effectively eliminate the measurement error caused by vibration and improve the reliability and service life of the sensor.

Resolution:

Refers to the displacement represented by the last digit of the sensor measurement output value.

Hysteresis:

Here it refers to the difference between the two measurement output values when the magnetic ring or measuring rod reaches and exceeds a certain position along the measurement stroke direction and then passes through this position in the reverse direction. The actual hysteresis of most types of sensors is very small and can be ignored in most applications.

Electrical protection level:

The IP (Ingress Protection) standard for protection against intrusion of enclosures issued by the International Electrotechnical Commission. For a detailed description of the IP standard, please refer to the official website of the IEC.

Range:

The range refers to the actual usable detection area of the displacement sensor, which is usually clearly indicated in the order model. Due to the existence of measurement blind areas at the beginning and end, the detection length (stroke) must be shorter than the total length of the sensor.

Temperature drift:

Temperature drift refers to the phenomenon that after the working environment temperature of the sensor changes, the measured value remains unchanged but the measurement output value changes. When used within the marked working temperature range, the temperature drift of the sensor can almost be ignored.

Temperature coefficient:

Refers to the amount of change in the sensor output value when the environment temperature changes by 1°C when the position of the measured target remains unchanged. The unit of temperature coefficient is ppm/°C (parts per million per degree Celsius).