JJF 1560-2016Calibration Specification for Multi-component Force Transducer (English PDF)

1 Scope (1)

2 References (1)

3 Terms and units of measurement (1)

4 Overview (1)

5 Metering characteristics (1)

6 Calibration conditions (2)

7 Calibration items and calibration methods (3)

8 Calibration results (7)

9 Re-school time interval (7)

Appendix A Multi-component Force Sensor Calibration Record (8)

Appendix B Measurement of Uncertainty in Measurement of Sensitivity Calibration Results (11)

Appendix C Evaluation of Uncertainty in Measurement of Coupling Errors in Output Sensitivity for Two-Component Combination Calibration (14)

Introduction

This specification is based on the rules set forth in JJF 1071-2010 "Rules for the Preparation of National Metrological Calibration Standards".

The calibration standard in the development process reference JJF (military) 20-2012 "multi-component dynamometer calibration specification" JJG391-2009 "Force Sensors" JJG632-1989 Terms, symbols and definitions in "Dynamic Force Sensors" and related technical requirements. This specification gives calibration conditions for calibration of multistage force sensors, calibration items and calibration methods.

This specification is the first release.

Multi - component force sensor calibration specification

1 Scope

This specification applies to static calibration of piezo-type and strain-type multi-component force sensors.

2 reference file

This specification refers to the following technical documents.

JJG391-2009 force sensor Dynamic Force Sensors JJG632-1989 Force and hardness measurement terms and definitions JJF (military) 20-2012 multi - component dynamometer calibration specification for dated references, only the dated edition applies to this specification; references that are not dated , The latest version (including all modifications) applies to this specification.

3 terms and units of measurement 3.1 single component calibration calibrationofacomponent A process of calibrating a component of a multi-component force sensor individually.

3.2 multi-component calibration calibrationofmulti-component A process of applying a load to two or more components of a multi-component force sensor.

3.3 coupling error when a component load is applied to the sensor, the change in the load of the other component load caused by the other component is rated negative the ratio of the output under the charge.

4 Overview

The multi-component force sensor refers to a force that can simultaneously measure at least two of the six generalized force components of the force vector sensor.

5 measurement characteristics Multi-component force sensor measurement characteristics in Table 1.

Table 1 Metrological characteristics

No. metering attribute name 1 zero output 2 back to zero difference 3 rated output

Table 1 (continued)

No. metering attribute name

4 Output sensitivity 5 repeatability 6 lag

7 Straightness

8 coupling error

6 calibration conditions

6.1 Environmental conditions Ambient temperature. 15 °C ~ 25 °C Relative humidity. <= 80% Other conditions. Calibration should not have interference sources that affect the calibration results.

6.2 Equipment for calibration the equipment used for calibration shall be calibrated (or calibrated) by the measuring technology body to meet the calibration requirements and shall be valid During the period, the range should be covered by the calibrated multi-component force sensor measurement range.

6.2.1 Multi-component force sensor calibration device the measurement uncertainty of the component complex value is less than the uncertainty of the corresponding component of the calibrated multi-component force sensor the degree of 1/3.

6.2.2 Force standard machine the uncertainty of the force value is less than 1/3 of the uncertainty of the corresponding measure of the multi-component force sensor.

6.2.3 Torque standard device the torque uncertainty is less than 1/3 of the uncertainty of the corresponding measure of the multi-component force sensor.

6.2.4 energize the power supply Multi-component force sensor calibration used in the excitation power supply output voltage 4h stability, should not exceed the multi-component force 1/5 of the corresponding accuracy of the sensor.

6.2.5 Indicator

Multi-component force sensor calibration instructions used in the instrument (including the multi-component force sensor to provide the excitation voltage Indicating the instrument) the accuracy of the relevant indicators, in principle, should not exceed the school multi-component force sensor corresponding accuracy indicators

6.2.6 Charge amplifier the maximum allowable error of the relevant technical indicators shall not exceed the corresponding accuracy index of the multi-component force sensor

6.2.7 Data acquisition system the data acquisition system shall have a multi-channel synchronous sampling function whose number of channels shall not be less than that of the multi-component force sensor and the sum of the number of data output channels of the calibration device. The sampling frequency of the data acquisition system should be no less than that of the multi-component force sensor when the output signal frequency of 20 times.

6.2.8 special fixture the relative measurement of the effective length between the individual loading positions of the special fixture and the force point of the multi-component force sensor itself is not the degree of determination should be less than 0.05% (k = 2).

7 Calibration items and calibration methods

7.1 Preparation before calibration

7.1.1 Determine the calibration items the calibration items can be selected according to the intended use of the multi-component force sensor, and the deviation from the calibration specification should in the calibration certificate.

7.1.2 Place time

The sensor should be placed under the specified environmental conditions for a sufficient period of time, the recommended placement time of not less than 8h.

7.1.3 Installation and loading conditions in accordance with the requirements of the instructions, the special fixture and multi-component force sensor installed correctly.

When the load should ensure that the multi-component force sensor axis and the load axis coincide, so that the tilt load and eccentric negative the effect of the Dutch is minimized.

7.1.4 Connection and preheating Before the calibration must be in accordance with the correct wiring method will be multi-component force sensor connected to the instrument, the excitation power Etc., adjust the excitation power, adjust the output voltage to the multi-component force sensor specified excitation voltage, and Preheating. The warm-up time should be in accordance with the requirements of the instructions.

Note. The manual does not specify the warm-up time, the multi-component force sensor, indicating the instrument, the excitation power and other general preheat 0.5h ~ 1h.

7.1.5 Preload

According to the multi-component force sensor manual and other information to confirm the calibration component and the measurement range of each component.

Preload is applied before each component is calibrated, and the hold time is typically 30 s.

7.1.6 Calibration range and calibration point selection the calibration range of each component is generally zero load to rated load, or according to user needs to determine the calibration of each component Point generally less than 5 points (including zero load point), generally take the rated load of 0%, 10%, 20%, 50% 100%, or according to user needs to determine.

7.2 Zero output

7.2.1 Preload is carried out in accordance with 7.1.5 and the zero load output value after the last preload unloading is read.

7.2.2 The zero output of each component is calculated according to equation (1).

thetaZi

thetani ×

100% (1)

Where.

Zi --- zero output of i-th component,% FS;

i --- component number;

thetaZi --- apply the i-th component after the last preload of the corresponding component under zero load readings, mV, V;

thetani --- i The average weight of the output under rated load, mV, V.

7.3 back to zero difference

7.3.1 Preloading in accordance with 7.1.5, reading the zero load of the indicator before and after the last preload Out of value.

7.3.2 The zero return of each component is calculated according to formula (2).

Zri =

thetaZi-theta'Zi

thetani ×

100% (2)

Where.

Zri --- the i component of the zero back,% FS;

theta'Zi - apply the i-th component to the last preload before the corresponding component under zero load, mV, V.

7.4 Rated output

7.4.1 Determine the amount of calibration, adjust the indicator parameters as needed, and read the zero load output.

7.4.2 Three preloads are applied continuously, after each unloading, check the indicator back to zero, readjust and record the zero load Output value.

7.4.3 Apply the load to the calibration points in increments of load until the rated load. Calibrate at each level After the charge reaches, keep a certain time, keep the time generally take 30s.

7.4.4 After the rated load is reached, the load is unloaded in descending order of load until zero load. At the time of calibration, the load is reached at each level After that, keep a certain time, keep the time generally take 30s. After returning to zero load, keep it for 30s, read and adjust Indicator zero.

7.4.5 Repeat 7.4.3 ~ 7.4.4 three times.

7.4.6 Determine the next calibrated component, calibrate at 7.4.2 to 7.4.5 until all components have been calibrated.

7.4.7 The rated output of each component is calculated according to equation (3).

thetani = thetasi - thetaZi (3) where.

thetasi --- i-th component calibration, the average load under the rated load, mV, V;

thetaZi --- i-th component calibration, the average of the zero-load readings, mV, V.

7.5 Output Sensitivity

7.5.1 Synchronization with the calibration of 7.4.

7.5.2 For strain gauges, the output sensitivity of each component under rated load is calculated according to equation (4) Calculation.

Sri =

thetani

Where.

Sri - the sensitivity of the i - th component under rated load, mV/V;

Vi --- the i-th component calibration test measured at the beginning of the excitation voltage, V.

7.5.3 For piezo-type force sensors, the output sensitivity of each component under rated load is calculated according to equation (5) Calculation.

Sqi =

Vni Gi · Di

Fni

Where.

Sqi --- charge sensitivity at rated load under i-th component calibration, pC/N;

Vni - the i-th component is calibrated at the rated output under rated load, V;

Gi - the i-th component is calibrated by the charge amplifier set by the attenuation block reading, N/V or Nm/V;

Di - the i-th component is calibrated when the charge amplifier is set to the normalized reading, pC/N;

Fni --- rated load of the i-th component, N or Nm.

7.6 Repeatability

7.6.1 Synchronization with the calibration of 7.4.

7.6.2 Repetition of each component is calculated according to equation (6).

deltathetaRi

thetani ×

100% (6)

Where.

Ri --- repeat of the i-th component,% FS;

deltathetaRi --- the i-th component in the process of repeated calibration of the load point of the output of the difference, mV, V.

7.7 lag

7.7.1 Synchronization with the calibration of 7.4.

7.7.2 The hysteresis of each component is calculated according to equation (7).

deltathetaHi

thetani ×

100% (7)

Where.

Hi --- the i component of the lag,% FS;

deltathetaHi --- the maximum value of the deviation calibration curve of the i-th component and the deviation of the process calibration curve, mV, V.

7.8 Straightness

7.8.1 is synchronized with the calibration of 7.4.

7.8.2 The straightness of each component is calculated according to formula (8).

deltathetaLi

thetani ×

100% (8)

Where.

Li --- the straightness of the i-th component,% FS;

deltathetaLi --- the i-th component of the process of the average calibration curve and the average endpoint of the maximum deviation, mV, V.

7.9 coupling error

7.9.1 Determine the combination scenario

7.9.1.1 The component combinations of the multi-component force sensors are shown in Table 2.

Table 2 Component composition of multi-component force sensor

Main component

Influence component

Fx Fy Fz Mx My Mz

Note.

1 in the table "" means that the combination can be achieved, "-" means that the combination can not be achieved;

2 main component refers to the calibration process in the arbitrary selection of a component, according to certain principles (such as user requirements or vulnerable to other components Affect) Select another or several components to load as an impact volume to calibrate the effect of the influence on the selected principal component.

7.9.1.2 Select the component to be calibrated and select all or part of the combined test according to the user's requirements.

7.9.1.3 Select the primary load and the zero load point of the affected component as the first calibration point, or apply one as needed After the preload is set, the indicator is cleared as a zero load calibration point.

7.9.1.4 For each combination, the load point can be selected within the range of the principal component as needed.

Component measurement range according to user needs to select the load point for combination test.

7.9.1.5 When performing two-component combination calibration, the remaining components are separately added under the principal component loading conditions Charge, respectively, to calibrate the coupling of these components to the principal component of the error.

7.9.2 Calibration procedure

7.9.2.1 Apply the maximum value of the selected component load on the multi-component force sensor and then unload the zero load, Apply the preload process 3 times.

7.9.2.2 Record the value of each component under zero load.

7.9.2.3 In accordance with the selected calibration scheme, first apply a primary component, at the first level load (including the zero load point) plus After that, read the output value of each component.

7.9.2.4 Each load (including zero load point) of each influence component is gradually applied, and the load the output value of each component of the component force sensor, until the maximum load after the removal of the impact of components, read the output value of each component.

7.9.2.5 Apply the subordinate load of the main component, read the output value of each component, and then the impact component according to 7.9.2.4 of the combined test.

7.9.2.6 Apply the other load points selected by the main component in sequence, subject to the provisions of 7.9.2.5 for the main component of other negative the combination test of the load points until the selected principal component of the load point combination test is completed, the load of all components are Unloaded to zero load, read the output of each component.

7.9.2.7 Other selected principal component combinations shall be tested in accordance with 7.9.2.2 to 7.9.2.6.

7.9.3 Calculate the calibration results the coupling error of each component is calculated according to equation (9).

CSij =

deltathetaCij

thetani ×

100% (9)

Where.

CSij --- affect the component j on the main component of the output sensitivity of the impact of% FS;

deltathetaCij - the average value of the process when the individual load points (including the zero load point) of the principal component i are applied separately when the application of the load component j after the load after the main component of the corresponding load point of the output process of the average value of the show the maximum value of the difference, mV, V, N, Nm.

8 Calibration results are expressed the calibration results should be reflected in the calibration certificate or calibration report. The calibration certificate or report shall include at least the following information.

a) title, "calibration certificate";

b) laboratory name and address;

c) where the calibration is made (if the address is different from the laboratory);

d) the identity of the certificate or report (such as number), the identity of each page and the total number of pages;

e) the name and address of the sending school unit;

f) the description and clear identification of the school object;

g) The date of calibration, if relevant to the validity and application of the calibration results, shall indicate the Date

h) If the results of the calibration results are relevant and the application is concerned, the sampling procedure of the school sample should be described;

i) the identification of the technical specifications on which the calibration is based, including the name and code;

j) the traceability and validity of the measurement standards used for this calibration;

k) description of the calibration environment;

l) Calibration results and their measurement uncertainty;

m) a description of the deviation from the calibration specification;

n) the signature, title or equivalent mark of the certificate or calibration report issuer, and the date of issue;

o) The calibration result is only a statement that is valid for the school object;

p) No part of the reproduction of a certificate or a statement of the report without the written approval of the laboratory.

The calibrated multi-component force sensor sends a calibration certificate or calibration report with a calibration seal.

9 re-school time interval as the length of the resumption of the time interval is the use of the instrument, the user, the quality of the instrument itself and other factors Decision, therefore, school units can be based on the actual use of the decision to re-school time interval, re-school time interval to build for one year.

Appendix A

Multi - component force sensor calibration record Entrusted by. Address.

Product Name. Model, Specification. Number.

Manufacturer. Temperature. °C Relative Humidity.% Calibration basis. JJF 1560-2016 "multi-component force sensor calibration specification"

Table A.1 Single component calibration records

load

Direction indicator readings Process backhaul 1 2 3 level 1 2 3 level Linear error measuring uncertainty (k = 2) Back to zero Back to zero difference Measuring range Calibration Standard. Model. Number. Valid.

Calibration. Verification. Calibration Date.

Table A.2 Multi-component combination calibration records

Calibration Standard. Model. Number. Valid.

Main component

The coupling effect on the principal component Influence quantity load principal component output influence quantity output correct Coupling error Back to zero difference

Table A.3 Calibration Certificate Inner Page Format

Calibration component Measurement point indication mean value indication repeatability delay linearity error Measuring range Back to zero difference Coupling error Fx Fy Fz Mx My Mz Fx -Fy -Fz -Mx -My -Mz -Appendix B Evaluation of Uncertainty in Measurement of Output Sensitivity Calibration Results B.1 Measurement model the output sensitivity is calculated according to the formula (B.1).

Sri =

thetani

Where.

Sri - Multi - component force sensor The i - th component is individually calibrated with the output sensitivity at rated load, mV/V;

thetani --- multi-component force sensor i-th component independent calibration under the rated load of the average output, mV;

Vi - the average value of the excitation voltage when the i-th component of the multi-component force sensor is individually calibrated.

B.2 Sensitivity Coefficient According to the uncertainty propagation law, Sri's synthetic standard uncertainty is calculated according to the formula (B.2).

uc (Sri) = c2 (thetani) × u2 (thetani) c2 (Vi) × u2 (Vi) (B.2) the sensitivity coefficient is calculated according to the formula (B.3) and (B.4).

c (thetani) =

c (Vi) = -

thetani

Vi2

B.3 Uncertainty Source Analysis the source of B.3.1 u (thetani) is as follows.

a) the measurement uncertainty introduced by the repeatability of the indication u1;

b) measurement uncertainty introduced by the force standard device u2;

c) indicates the measurement uncertainty u3 of the ...