Page 15 of catalogue Linear inductive displacement sensors of Micro-Epsilon Messtechnik GmbH & Co. KG

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Inductive displacement and Position sensors terms and definitions
Adjustment: Calibration: Cut-off frequency: Linearity: Setting or balancing a measurement device to remedy as far as possible systematic measurement deviations as required by the intended application. Determination of the relationship between the measurement, the output quantity and the associated true or correct value. The cut-off frequency is the frequency at which the output signal reduces to a certain value (-3 dB = 70.7 %) below the reference value. The linearity states the percentage deviation of the electrical output from the required ideal straight line. Linearity figures are given as absolute or independent linearity. With the determination of the absolute linearity the reference line is placed through the theoretical zero and end points of the output signal. The absolute linearity is then taken as the maximum deviation of the measurements recorded in the system final inspection to these reference straight lines. This method is used with the systems in the EDS series. When determining the independent linearity, first the linearity of the measurements taken during the final inspection of the systems are recorded. Using these recorded measurements, a reference straight line is drawn by means of a compensation calculation (method of the smallest maximum deviation). The independent linearity is then specified as the maximum deviation of the recorded measurements to this reference straight line. This method is used with the systems in the LVDT, VIP LVP and LDR series. , Measurement object: Measurement range: The measurement object is the body whose movement, position or dimension is to be acquired by the sensor. The measurement range is the total calibrated range which is converted into a signal by the following electronics with the specified limits. Beyond the defined measurement range the signal values within certain limits are output with reduced accuracy. Disturbance signal which is superimposed on the output signal. Quantitative specification of the deviation of mutually independent measurements which are determined under repeat conditions. The resolution of a measurement device states the value of the input quantity at which a clear differentiation can be made between two measurements that lie close together. Sensitivity is defined as the ratio of the signal change of the measurement transducer and the change of the physical input quantity. Sensitivity= Change of the measurement transducer signal Change of the physical input quantity

Noise: Repeatability: Resolution: Sensitivity:

With Inductive sensors without integrated electronics the sensitivity is stated in mV / V / mm. This means that the sensitivity of the sensor is specified per mm displacement per volt of excitation voltage. Spring constant: With LVDT gaging Sensors which contact the part to be measured with the plunger, the measuring force of the plunger is calculated using the spring constant. The restoring force of the spring is proportional to the deflection. Material which influences the electromagnetic properties of the coil: The target is realized as a core, ring or sleeve and is joined to the measurement object. Relative change of the output signal in dependence of the temperature.

Target: Temperature stability: