- Use the sub-item indicator method to introduce the technical parameters of the load cell. The traditional method is to use the sub-item index. The advantage is that the physical meaning is clear, and it has been used for many years, and many people are familiar with it. We now list its main items as follows: *The upper limit value of the weighing range given by the rated capacity manufacturer.
*Rated output (sensitivity)
The difference between the output signal of the sensor when the rated load is applied and when there is no load. Since the output signal of the load cell is related to the applied excitation voltage, the unit of the rated output is expressed in mV/V. And call it sensitivity.
*Sensitivity Tolerance
The percentage of the difference between the actual stable output of the sensor and the corresponding nominal rated output to the nominal rated output. For example, the actual rated output of a load cell is 2.002mV/V, and the corresponding standard rated output is 2mV/V, then its sensitivity tolerance is: ((2.002–2.000)/2.000) *100%=0.1%
*Non-linear
The maximum deviation between the straight line determined by the output value of no load and the output value at rated load and the measured curve of increasing load is the percentage of the rated output value.
*Lag Tolerance
Gradually load from no load to rated load and then gradually unload. The percentage of the maximum difference between loading and unloading output at the same load point to the rated output value.
*Repeatability Error
Under the same environmental conditions, repeatedly load the sensor to the rated load and unload it. The percentage of the maximum difference of the output value at the same load point during the loading process to the rated output.
*Creep
When the load is constant (generally taken as the rated load) and other test conditions remain unchanged, the percentage of the load cell output change over time to the rated output.
* Zero Output
Under the recommended voltage excitation, the output value of the sensor is the percentage of the rated output when no load is applied.
*Insulation Resistance
The DC resistance value between the sensor circuit and the elastomer.
*Input Resistance
When the signal output terminal is open circuit and the sensor is not loaded, the impedance value measured from the power supply excitation input terminal.
*Output Impedance
The impedance measured from the signal output terminal when the power excitation input terminal is short-circuited and the sensor is not loaded.
*Temperature Compensation Range
Within this temperature range, the sensor's rated output and zero balance are tightly compensated so as not to exceed the specified range.
*Influence of Zero Temperature
Changes in zero balance caused by changes in ambient temperature. Generally, it is expressed as a percentage of the zero balance change to the rated output when the temperature changes by 10K.
*Influence of Rated Output Temperature
The change of rated output caused by the change of ambient temperature.
Generally, it is expressed as a percentage of the rated output of the rated output change caused by every 10K change in temperature.
*Operating Temperature Range
The sensor will not produce permanent harmful changes in any of its performance parameters within this temperature range
2. Terms used in "International Recommendation No. OIML60". Based on the 1992 edition of "OIML No. 60 International Proposal", refer to the new technical parameters of "JJG669--90 Load Cell Verification Regulations":
* Load Cell Output
The measurable (mass) obtained through the conversion of the load cell can be measured.
*Graduation Value of Load Cell
The size of one part after the measuring range of the load cell is divided into equal parts.
*Verification Division Value of Load Cell (V)
For the purpose of accuracy grading, the scale value of the load cell expressed in mass units is used in the load cell test.
*The Minimum Verification Division Value of the Load Cell (Vmin)
The measuring range of the load cell can be divided by the minimum verification division value.
*Minimum Static Load (Fsmin)
The minimum value of mass that can be applied to a load cell without exceeding the maximum allowable error.
*Maximum Weighing
The maximum value of mass that can be applied to a load cell without exceeding the maximum allowable error.
* Nonlinear (L)
The deviation between the process calibration curve of the load cell and the theoretical straight line.
*Lag Error (H)
The maximum difference between the output readings of the load cell when the same level of load is applied; one of them is the process reading starting from the minimum static load, and the other is the return reading starting from the maximum weighing.
*Creep (Cp)
When the load is constant and all environmental conditions and other variables are also held constant, the change in the full load output of the load cell over time.
*Minimum Static Load Output Recovery Plant (CrFsmin)
Before the load is applied 1. When introducing the technical parameters of the load cell with the sub-item index representation method, the traditional method is to use the sub-item index. The advantage is that the physical meaning is clear, and it has been used for many years, and many people are familiar with it. We now list its main items as follows: *The upper limit value of the weighing range given by the rated capacity manufacturer.
*Rated Output (sensitivity)
The difference between the output signal of the sensor when the rated load is applied and when there is no load. Since the output signal of the load cell is related to the applied excitation voltage, the unit of the rated output is expressed in mV/V. And call it sensitivity.
*Sensitivity Tolerance
The percentage of the difference between the actual stable output of the sensor and the corresponding nominal rated output to the nominal rated output. For example, the actual rated output of a load cell is 2.002mV/V, and the corresponding standard rated output is 2mV/V, then its sensitivity tolerance is: ((2.002–2.000)/2.000) *100%=0.1%
*Non-linear
The maximum deviation between the straight line determined by the output value of no load and the output value at rated load and the measured curve of increasing load is the percentage of the rated output value.
*Lag Tolerance
Gradually load from no load to rated load and then gradually unload. The percentage of the maximum difference between loading and unloading output at the same load point to the rated output value.
*Repeatability Error
Under the same environmental conditions, repeatedly load the sensor to the rated load and unload it. The percentage of the maximum difference of the output value at the same load point during the loading process to the rated output.
*Creep
When the load is constant (generally taken as the rated load) and other test conditions remain unchanged, the percentage of the load cell output change over time to the rated output.
* Zero Output
Under the recommended voltage excitation, the output value of the sensor is the percentage of the rated output when no load is applied.
*Insulation Resistance
The DC resistance value between the sensor circuit and the elastomer.
*Input Resistance
When the signal output terminal is open circuit and the sensor is not loaded, the impedance value measured from the power supply excitation input terminal.
*Output Impedance
The impedance measured from the signal output terminal when the power excitation input terminal is short-circuited and the sensor is not loaded.
*Temperature Compensation Range
Within this temperature range, the sensor's rated output and zero balance are tightly compensated so as not to exceed the specified range.
*Influence of Zero Temperature
Changes in zero balance caused by changes in ambient temperature. Generally, it is expressed as a percentage of the zero balance change to the rated output when the temperature changes by 10K.
*Influence of Rated Output Temperature
The change of rated output caused by the change of ambient temperature.
Generally, it is expressed as a percentage of the rated output of the rated output change caused by every 10K change in temperature.
*Operating Temperature Range
The sensor will not produce permanent harmful changes in any of its performance parameters within this temperature range
2. Terms used in "International Recommendation No. OIML60". Based on the 1992 edition of "OIML No. 60 International Proposal", refer to the new technical parameters of "JJG669--90 Load Cell Verification Regulations":
* Load Cell Output
The measurable (mass) obtained through the conversion of the load cell can be measured.
*Graduation Value of Load Cell
The size of one part after the measuring range of the load cell is divided into equal parts.
*Verification Division Value of Load Cell (V)
For the purpose of accuracy grading, the scale value of the load cell expressed in mass units is used in the load cell test.
*Weighing Sensor*Minimum Verification Division Value (Vmin)
The minimum verification scale value that the load cell measuring range can be scaled.
*Minimum Static Load (Fsmin)
The minimum value of mass that can be applied to a load cell without exceeding the maximum permissible error.
*Maximum Weighing
The maximum value of mass that can be applied to a load cell without exceeding the maximum permissible error.
* Nonlinear (L)
The deviation between the process calibration curve of the load cell and the theoretical straight line.
*Lag Error (H)
The maximum difference between the output readings of the load cell when the same level of load is applied. One of them is the process reading starting from the minimum static load, and the other is the return reading starting from the maximum weighing.
*Creep (Cp)
When the load is constant and all environmental conditions and other variables are also held constant, the change in the full load output of the load cell over time.
*Minimum Static Load Output Recovery Plant (CrFsmin)
The difference between the minimum static load output of the load cell measured before and after the load is applied.
*Repeatability Error (R)
Under the same load and the same environmental conditions, the difference between the output readings of the load cell obtained from several consecutive experiments.
*The Influence of Temperature on the Minimum Static Load Output (Fsmin)
The change between the minimum static load output due to the change of ambient temperature.
*Influence of Temperature on Output Sensitivity (St)
Changes in output sensitivity due to changes in ambient temperature.
*Measuring Range of Load Cell
The measured (quality) value range within which the measurement result will not exceed the maximum allowable error.
*Safe Limit Load
The maximum load that can be applied to the load cell. At this time, the load cell will not produce permanent drift beyond the specified value in terms of performance characteristics.
*Influence of Temperature and Humidity on Minimum Static Load Output (FsminH)
The change of the minimum static load output due to the change of temperature and humidity.
*Influence of Temperature and Humidity on Output Sensitivity
Changes in output sensitivity due to changes in temperature and humidity.
In addition, in the "JJG699-90 Load Cell Verification Regulations", a technical parameter is also listed, namely
*Minimum Load (Fmin)
The mass value closest to the minimum static load of the load cell that the force generating device can achieve.
It is precisely because the sensor measurement is always carried out on the dynamometer, and it is difficult to directly measure the performance of the minimum static load point. One more point, "OIML60 International Proposal" is specially formulated for load cells, and its starting point for the evaluation of load cells is to adapt to the requirements of weighing instruments.
, after measuring the difference between the minimum static load output of the load cell.
*Repeatability Error (R)
Under the same load and the same environmental conditions, the difference between the output readings of the load cell obtained from several consecutive experiments.
*The Influence of Temperature on the Minimum Static Load Output (Fsmin)
The change between the minimum static load output due to the change of ambient temperature.
*Influence of Temperature on Output Sensitivity (St)
Changes in output sensitivity due to changes in ambient temperature.
*Measuring Range of Load Cell
The measured (quality) value range within which the measurement result will not exceed the maximum allowable error.
*Safe Limit Load
The maximum load that can be applied to the load cell. At this time, the load cell will not produce permanent drift beyond the specified value in terms of performance characteristics.
*Influence of Temperature and Humidity on Minimum Static Load Output (FsminH)
The change of the minimum static load output due to the change of temperature and humidity.
*Influence of Temperature and Humidity on Output Sensitivity
Changes in output sensitivity due to changes in temperature and humidity.
In addition, in the "JJG699-90 Load Cell Verification Regulations", a technical parameter is also listed.
*Minimum Load (Fmin)
The mass value closest to the minimum static load of the load cell that the force generating device can achieve.
It is precisely because the sensor measurement is always carried out on the dynamometer, and it is difficult to directly measure the performance of the minimum static load point. One more point, "OIML60 International Proposal" is specially formulated for load cells, and its starting point for the evaluation of load cells is to adapt to the requirements of weighing instruments.
Post time: Mar-30-2023