GB/T 30083-2013Copper, lead and zinc ores and concentrates -- Precision and bias of mass measurement techniques (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules.

This standard uses the translation method identical with ISO 12745:2008 "The precision and bias of copper, lead and zinc concentrates and methods of measurement." this standard and ISO 12745:2008 The main differences are as follows.

--- With a decimal point instead of a comma as the decimal point in the international standard ",". ",";

--- Use the "standard" instead of "this International Standard";

--- According to Chinese customary change the standard name;

--- Remove the cover of the international standards, directory, foreword and introduction.

This standard by the national non-ferrous metals Standardization Technical Committee (SAC/TC243) centralized.

1 Scope

This standard specifies the calculation method bias, precision, and a method of metering the resulting quality of the various methods of measurement precision.

This standard is based on a statistical validation of measurement methods by unbiased data, calculate the variance measure of its precision and examined within its operating range Linearity of measurement based on. The calibration method and results of performance testing using the applicable provisions of the quantitative measurement methods can be used to fine and to determine the linear density and deviation measuring device.

The standard deviation is used to calculate the vehicle or concentrate shipping wet weight measurement method, as the two sides trade transport, insurance, pre-paid and most end the basis for calculation.

Static scale applications require at least not less than 1t quality of the goods in order to check, and that the quality should be consistent with the scale range. With a series of cover Cover the entire weighing device quality standard was applied load operating range as to estimate its precision and detect its entire operating range of linear, indeed Recognize its calibration status process.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 3358.1-2009 Statistics Vocabulary and symbols - Part 1. General statistical terms and terms used in probability (ISO 3534.1, IDT) GB/T 3358.2-2009 Statistics Vocabulary and symbols - Part 2. Applied Statistics (ISO 3534.2, IDT) GB/T 6379.1-2004 measurement methods and results of Accuracy (trueness and precision) Part 1 General principles and definitions (ISO 5725.1, IDT)

3 Terms and Definitions

The following terms and definitions apply to this document.

Note 1. In the application of the statistical authority of books, sigma2 only used only for an unknown population variance estimation of the measurement process. On the contrary, the symbol for the sample variance s2 and Thus limiting the adjustment measurements. The standard method of bulk sampling or sigma sigma2 often used to distinguish.

Note 2. The following definitions of the most commonly used measurement technology concepts and terminology, and to clarify the risk of cargo damage gain the possibility of quantitative methods and standard commercial transport Non-standard expected difference between the method used.

Accuracy

Quality measurement results and the degree of consistency between the true value.

Note. Accuracy can not be measured abstraction, but by bias or systematic error can be quantified accuracy deviation measured.

Bias bias

Expectations and accept the results of the difference between the reference value.

Note. This definition is valid only when accepted reference value is known and has the absolute degree of certainty (quality and length of international units). Suppose accepted reference value limited Within the confidence limits are known and accepted reference test results fall within the expected value of the confidence limits than expected and accepted reference value is the difference between the test results deviation. For example, typically granted only by the quality of one measurement, the measurement value is not expected. This standard deviation is granted independence wet weight Estimated statistically significant difference between the values (loading and unloading, called static and dynamic said), and quality measurement should as much as possible by the most direct Money transfer dates back to the national prototype kilogram and the quality of international units.

Belt scales beltscale the goods on the belt through the inner conveyor section hanging scales continuously accumulated and recorded in the cumulative mass metering device.

NOTE. The belt scale is a continuous metering device calibration method. applied load, such as calibrated chain (dynamic) on the segment portion of the belt weigher, or standard quality material Hanging in the balance after a certain frame accumulation period (static), or with a belt measuring scales have weighing scales from static quality of the material (material weighing method).

Deviation detection limit (BDL) biasdetectionlimit T test or inspection system deviation plus loads and loads measured deviation between capacity and sensitivity.

The coefficient of variation (CV) coefficientofvariation Measuring measurement methods of stochastic volatility, the standard deviation value equal to a percentage of the measurement quality.

Confidence interval (CI) confidenceinterval A certain confidence level, including all possible difference measurements and the mean of their range.

Confidence Range (CR) confidencerange A certain confidence level, including all measurements, including the possible range.

NOTE. science and engineering generally use 95% confidence intervals and scope.

The correlation coefficient (r) correlationcoefficient Measuring a series of standard quality was measured and the correlation between loads or independence.

Water gauge measuring draftsurvey Based on a measurement method to convert the difference freighter under different loading conditions to mass displacement, the method must be established taking into account the water Density, temperature and ballast and ballast supply and the impact of changes in water gauge table.

Note. The water gauge is measured based on Archimedes' principle, which floats suffered buoyancy equal to its gravity. Quality goods can be shipped by water gauge, parallax, press Changes cabin was consumed and the supply was converted to mass measured according to the ship's water gauge table.

3.10

Precision

Measurement methods of the cumulative effect of random fluctuations.

Note. The precision is a special word, such as "high-precision", "low precision" and "high precision quality", although no quantitative information but they are effective description.

3.11

Possible deviation range (PBR) probablebiasrange for only the risk class I or II I type and category of risk is measured deviation located at a predetermined probability condition limits.

3.12

Relative standard deviation (sr) relativestandarddeviation Measuring measurement methods of random fluctuations, numerically equal to the standard deviation divided by the measurement quality.

3.13

Standard deviation (s) standarddeviation Measuring measurement methods of random fluctuations, numerically equal to the square root of the variance.

3.14

Static scale Would, or funnel suspended gantry static load converted to mass metering device or platform on the scales.

Note. static scale batch type measuring device using a single standard weights or calibration correction hydraulic device. Static scale can automatically zero, so that by the tare and the difference between gross and accumulated to quality. Double hopper scales can achieve approximate continuous mass flow during loading and unloading operations without sacrificing the accuracy and static scales Precision quality.

3.15

T-test (t) Student'st-value Series than the difference between the standard deviation of the mean difference between the applied load and average load measurements mean.

3.16

Class I risk (alpha) typeIrisk when the mean difference is statistically equivalent to zero, assuming a series of applied load and average load measurement is consistent, alpha to reject the hypothesis risk.

3.17

II class risk (beta) typeIIrisk when the mean difference statistically not zero, assuming a series of applied load and average load measurement is consistent, beta risk to reject the hypothesis.

3.18

Variance (s2) variance Measuring measurement methods of stochastic fluctuations, each equal to the measured data and the mean squared difference between the value divided by the number of measurements minus one (degree of freedom n-1).

Note. Applied Statistics Textbooks term "mean square deviation from the mean value obtained" is often used to denote the variance.

4 Subjects

International or national manual metering device defines uncertainty of measurement technology. In some manual, "bias" is defined as "error Poor "or" systematic error ", while others refer to" the maximum allowable risk "and" tolerance ", respectively, as a measuring method for the determination of random variance Methods.

Unless the "maximum tolerance" or "tolerance" is exactly equal to 95% or 99% confidence interval, otherwise it can not be converted to a measure Variance precision metering process basic instruments. Nevertheless, as a measure of trade between the two sides at risk, given only concentrates wet the exact value of the weight variance to be calculated to give a dry weight at 95% confidence interval and scope and precision metal content.

Water gauge measuring 4.1 Before and after loading and unloading ships displacement distribution is converted into water gauge table with a wet weight basis. Such as for ballast and fuel, fresh water, make up and other changes to the consumables need to be amended. To difference under different loading conditions of ship displacement into quality, but also need to gauge Ballast water and the average density of the water around the ship operator.

External factors such as wind speed and salinity stratification limits the water gauge measurement precision. When the boat is not fully laden hull deformation increases further Uncertainty thus may form a bias. Single cargo hold water gauge measurements are often not full tank measurement accuracy. When the ship without ballast and completely full or Water gauge measurements can get the highest precision when fully unloaded.

If the bilge water is discharged through a bilge water valve will then drift so that cargo weight discrepancies. In this case, when the discharge will be measured wet weight Significantly lower than when loading, unloading and dry weight before and after basically the same. The oxidation reaction is usually a small increase in quality, but high-precision measurement of water gauge Volatility so that it can be ignored.

2.5% In general, the coefficient of variation range from 0.5% evaluation of precision low to high. By comparing the handling of water gauge can be found in the lowest the coefficient of variation. If the water gauge inspector unloading know the bill of lading, water gauge measurement port of discharge and loading system no longer has Independence count on.

When measuring the water gauge is loaded on board officials and representatives of the transport side of the water gauge inspectors, sometimes on behalf of buyers between the water gauge inspector Consensus-based. In this case, the water gauge measuring precision loading time is incalculable. Only having two or more funding Quality water gauge inspector simultaneously but independently complete water gauge measurements in order to accurately estimate their precision.

Suppose goods free of moisture and mechanical losses do not cause bias, water gauge measuring precision can also be measured by a known static scale precision characteristics Wet weight to estimate the amount of cargo. Since the deformation difference carriers under different conditions of transport, water gauge can not be measured as static measurement apparatus having the same line Sexual relations.

Appendix C provides an example of a calculation by measuring the displacement of water gauge.

Belt scale measuring 4.2 Belt scale is a way to change over a long period of suspension belt segment load accumulated continuous (dynamic) of the metering device. Leather belt Precision and Bias scale measurement depends on a number of factors, rather than its operating environment. Belt scale calibration can be achieved by a metering mechanism the upper belt traction chain formed in said frame static weight, or the use of a certain quality is measured by the static scale too wet weight of the material.

Although relatively short time, but the use of dynamic material test weight is the most reliable method of calibrating scales.

A series belt scales and hopper scales integrated belt conveyor system, by comparing the wet weight of (static and dynamic) to be corrected and estimation accuracy. A pair of belt weigher series can have the following advantages. cargo carve into the transport mechanism and belt that can lead to suspension mechanism between Two measurements inconsistent. Determine anomalous difference can be corrected, the belt weigher removed periodically overflow can reduce drift and bias Likelihood of occurrence.

Under optimum conditions in the form of a coefficient of variation of the measured precision of 0.4%, but under conditions of risk coefficient of variation is likely to exceed 3.5%.

Under normal conditions, you can measure and control calibration before each measurement interval variance to obtain real and reliable belt weigher precision.

Frequent calibration ensures that the belt weigher get wet weight unbiased estimator. Central limit theorem dynamic continuous weighing scales precision wet weight Significantly lower than with static scale batches weighing.

Under normal circumstances linear belt scale is difficult to measure. Manufacturer of load cell response linearity 4mA ~ 20mA Fan Wai testing. Nevertheless, the linear test conditions does not ensure a linear load under normal circumstances. In addition to non-linear deviation will not be more than such as adding more uncertainty factors belt tension, hardness, thickness or wet material such as wind.