Home >Applications > Displacement sensorDisplacement sensor

1. Rated load: the rated load of the sensor refers to the maximum axial load that can be measured in the range of technical indicators when designing this sensor. However, when used in practice, it is generally only 2/3 to 1/3 of the rated range.

2. Allowable load (or safety overload): the maximum axial load that the sensor allows to apply. Allow overwork within a certain range. Usually is 120%~ 150%.

3. Ultimate load (or limit overload): the maximum axial load that the sensor can withstand without losing its ability to work. The sensor will be damaged when work exceeds this value.

4. Sensitivity: the ratio of output increment to the load increment. Normally, the output of the mV is rated at 1V input. When the company's products are matched with other company products, its sensitive coefficients must be consistent.

5. Nonlinearity: this is a parameter that represents the exact degree of the corresponding relationship between the voltage signal and the load.

6, Repeatability: add the same load repeatedly on the sensor under the same conditions over and over again, testing the output value can repeat or not, this feature is more important, more can reflect the quality of the sensor. The expression of the national standard is repeatability error can be determined with non-linear at the same time. Repeatability error of sensors (R) press type calculation: R=ΔθR/θn×100%. ΔθR - three times on the same site measurement of the biggest difference between the actual output value (mv).Like Soway linear displacement sensor, if the signal output is the voltage, the repeatability error is less than 0.01% F.S. When the signal output is a digital signal, the repeatability error is only 5μm.

7, Hysteresis: popular means: step by step of load and unload, corresponding to each level load, and ideally should have the same reading, but the truth isn’t consistent, the index of the disparity expresses with hysteresis error. National standard is to calculate hysteresis error like this: in the hysteresis error of sensors (H) press type calculation: H=ΔθH/θn×100%.ΔθH - three times on the same site actual output signal value arithmetic average and three times on the up stroke of the actual values of the output signal of the biggest difference between arithmetic average value (mv).

8, Creep and Creep recovery: requirements from the two aspects of testing sensor creep error: one is the creep: in 5 to 10 seconds without impact, combined with the rated load, the load after 5 ~ 10 seconds reading, and then according to certain time interval in 30 minutes, in turn, take notes on the output value. The sensor creep (CP) is calculated by the following formula: CP=θ2-θ3/θn×100%. The second is creep recovery: get rid of the rated load as soon as possible (in 5~10 seconds), then read immediately within 5~10 seconds after unloading, and then record the output value in the 30 minutes at a certain time interval. The creep recovery (CR) of the sensor is calculated by the following formula: CR=θ5-θ6/θn×100%.

9. Allowable temperature: the application of this sensor for the occasion. E.g., Room temperature sensor is labeled: - 20 ℃ - + 70 ℃. High temperature sensor is labeled: - 40 ℃ - + 250 ℃.

10. Temperature compensation scope: this sensor has been compensated at such temperature range. E.g., Room temperature sensor is marked for - 10 ℃ - + 55 ℃.

11. The zero point temperature influence (commonly known as zero temperature drift) : is characterized by the stability of its zero point when the temperature of the environment changes. General with every 10 ℃ range of drift as the measuring unit. 

12. Temperature effect of the output sensitive coefficient (known as coefficient temperature drift) : this parameter represents the stability of the sensor's output sensitivity when ambient temperature changes. General with every 10 ℃ range of drift as the measuring unit.

13, Output impedance: the company sensor with other company sensor are used in parallel, other manufacturers have to find out the company's products output impedance, this value must be consistent with, otherwise it will directly affect the output characteristics of the electronic scale and the corners of the error of debugging.

14, Input impedance: due to the elastic modulus compensation resistor of the sensor input end and sensitivity coefficient adjustion resistor, so the sensor input resistance is greater than the output resistance, but through the shunt resistance method to make it change. The input impedance of each sensor is required to conform. Work with the other manufacturer's sensors, should make consistent with the input impedance, otherwise in the debug error increases when calibrating, because the input impedance of the sensor is a load for regulated power supply, only the same load, the voltage of power supply is the same as regulated power supply can provide. 

15. Insulation impedance: insulation impedance is the equivalent of the sensor making bridge with ground using a corresponding resistance. The value of the insulation resistance affects the performance of the sensor. When the insulation impedance is below a certain value, the bridge will not work properly.

16. Recommended excitation voltage: generally 5~10 volts. The stable voltage supply in the general weighing instrument is 5 or 10 volts.

17. Maximum excitation voltage: to improve the output signal, in some cases (for example, large tare) requires greater excitation voltage to obtain larger signals. 

18. Cable length: it is related to the site layout, and the regular cable length of the company's products must be known before ordering. Also, notice whether the environment whether is corrosive, impact, high or low temperature. 

19. Seal protection grade IP67: anti-flooding effect, with the specified pressure and time immersed in the water, performance is not affected. The sensor of adhesive protection can reach IP67. Besides can prevent oil, waterproof, can also prevent general corrosive gas, corrosive medium. This sensor outputs a voltage signal that corresponds to the exact degree of the load.