This standard specifies the definition, classification, requirements, test methods, inspection rules and marking, packaging, transportation and storage of gravity-type automatic loading scales (quantitative automatic scales) (hereinafter referred to as "loading scales"). This standard applies to loading scales that automatically weigh bulk materials into a number of pre-specified, practically constant, and mutually separated loads. QB/T 2501-2000 Gravity-type automatic loading scales QB/T2501-2000 Standard download decompression password: www.bzxz.net
This standard specifies the definition, classification, requirements, test methods, inspection rules and marking, packaging, transportation and storage of gravity-type automatic loading scales (quantitative automatic scales) (hereinafter referred to as "loading scales"). This standard applies to loading scales that automatically weigh bulk materials into a number of pre-specified, practically constant, and mutually separated loads.

QB/T 2501—2000
In terms of technical content, this standard is equivalent to the International Organization of Legal Metrology (OIML) International Recommendation R61 "Gravimetric Automatic Loading Scale" 1996 (E).
This standard changes the "measurement control" in OIMLR61-1 to "inspection rules", deletes some tables in OIMLR61-2; and adds other contents required by GB/T1.3—1997. Appendix A and Appendix B of this standard are the appendices of the standard. This standard is proposed by the Industry Management Department of the State Bureau of Light Industry. This standard is under the jurisdiction of the National Technical Committee for Standardization of Weighing Instruments. The drafting units of this standard are: Changsha Weighing Instrument Factory of China Light Industry Machinery Corporation, Jinan Jinzhong Electronic Weighing Instrument Co., Ltd., Harbin Jieman Technology Development Co., Ltd., Qingdao Weighing Instrument Testing Center. The main drafters of this standard are: Xi Zhisan, Liu Junyi, Shen Liren, Han Jianjun, and Wang Junguo. 206
QB/T2501--2000
OIML Foreword
The International Organization of Legal Metrology (OIMIL) is a worldwide, intergovernmental organization whose main task is to coordinate the use of various international legal metrology organizations' procedures and metrology management by the metrology institutions or relevant organizations of each member country. OIML's publications are mainly divided into two categories:
1) International recommendations (OIML.R), which determine the characteristic requirements of measuring instruments, specify measurement methods and typical procedures for testing equipment. OIML member countries should implement these international recommendations as much as possible. 2) International documents (OIML: D), which are essentially information provided to improve the work of various measurement units. OIML recommendations and documents are jointly formulated by committees and branches composed of member countries and relevant international and regional organizations. The main purpose of the cooperation between OIML and certain organizations, such as ISO and IEC, is to avoid conflicts between technical requirements and to enable manufacturers, users and laboratories of measuring instruments to apply the publications of OIML and other organizations at the same time. International Recommendations and International Documents are published in French and English and are revised regularly. OIML publications can be obtained from the organization's headquarters. International Bureau of Legal Metrology
11, rue Turgot 75009 Paris, France
Tel: 33 (0) 148781282 and 42852711 Fax: 33 (0) 142821727
This publication - Revision of Standard OIMLR 61-1 1996 (E) has been prepared by OIMLTC9/SC2 Working Group "Automatic Weighing Instruments". This Recommendation was issued by the International Conference on Legal Metrology in 1995 and formally approved in 1996 to replace the 1985 version. 207 ||tt| |1Scope
Light Industry Standard of the People's Republic of China
Gravimetric Automatic Loading Scale
QB/T2501--2000
This standard specifies the definition, classification, requirements, test methods, inspection rules and marking, packaging, transportation and storage of gravimetric automatic loading scale (quantitative automatic weighing instrument) (hereinafter referred to as "loading scale"). This standard applies to loading scales that automatically weigh bulk materials into a number of loads with predetermined masses, which are actually constant and separated from each other.
1 This standard does not limit the maximum or minimum weighing capacity of the loading scale. 2 When the loading scale is used as a non-automatic scale, it shall meet the requirements of QIML International Recommendation R76 "Non-automatic weighing instruments". 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB191—1990 Pictorial signs for packaging storage and transportation
GB/T3797--1989 Electronic control equipment Part 2: Electronic control equipment equipped with electronic devices GB/T6388-1986 Shipping packaging delivery and receipt mark CB/T7551-1997 Weighing sensor
GB/T7724-1999 Weighing display controller
QB1563-—1992 Method for compiling weighing instrument product models 3 Definitions
This standard adopts the following definitions.
The definitions used in this standard are all from the "International Basic Vocabulary and General Terms of Metrology" (VIM 1993 version) and the "Legal Metrology Vocabulary" (VML 1978 version). The following explanations are only applicable to this standard. 3.1 Weighing instrument is a measuring instrument that uses the force of gravity acting on an object to determine the mass of the object. According to the mode of operation, weighing instruments are divided into automatic weighing instruments and non-automatic weighing instruments. 3.2 Automatic weighing instrument Automatic weighing instrument does not require operator intervention during the weighing process, but weighs automatically according to a predetermined processing procedure. 3.3 Automatic gravimetric filling instrument Automatic weighing instrument that divides bulk materials into many loads of predetermined mass, which are actually constant and separated from each other, and loads the loads into containers. It mainly includes one or more weighing units or one or more automatic feeding devices associated with them, as well as corresponding control devices and discharge devices.
Gravimetric automatic loading weighing instruments also include the following three types of weighing instruments: 3.3.1 Associative (selective combination) weighing instrument Approved by the State Bureau of Light Industry on December 1, 2000
Implemented on June 1, 2001
QB/T 2501--2000
A loading weighing instrument that includes one or more weighing units, calculates the corresponding load combination, and combines it as a single load and outputs it accordingly.
3.3.2 Cumulative weighing instrument A loading weighing instrument that has only one weighing unit and uses a device to control the secondary load through more than one weighing cycle. 3.3.3 Subtractive weighing instrument A loading weighing instrument that determines the load by controlling the discharge of the weighing hopper. 3.4 Mechanical and electronic fill weighing instrument Machinery and electronic fill weighing instrument A gravity-type automatic fill weighing instrument with a mechanical lever as the main force transmission device and controlled by an electronic device. 3.5 Electronic instrument Electronic instrument A weighing instrument equipped with an electronic device.
3.6 Control instrument A weighing instrument used to determine the mass of the test fill output by a fill weighing instrument. 3.7 Filling fill1
One or more loads are input into a container to form a predetermined mass. 3.8 Construction
Note: In this standard, the term "device" refers to any component that uses a certain method to perform one or more specific functions. 3.8.1 Weighing unit
A device that provides mass information of the load to be weighed, which can be composed of all or part of a non-automatic weighing device. 3.8.2 Load receptor
A component used to bear the load.
3.8.3 Feeding device
A device that provides bulk material to the weighing unit. The device may have one or more working modes. 3.8.4 Control devices3.8.4.1 Feed control deviceA device that adjusts the feeding rate of the feeder. 3.8.4.2 Fill setting deviceA device that allows the setting of a preset value.
3.8.4.3 Final feed cut-off deviceA device that controls the cut-off of the final feed so that the average mass of the feed meets the preset value. The device may have a function to adjust and compensate for the material falling in the air.
3.8.4.4 Correction deviceA device that automatically calibrates the setting value of the filling scale. 3.8.5 Electronic deviceA device composed of electronic components and capable of performing a specific function. It is usually made into an independent unit and can be tested separately. 3.8.6 Electronic sub-assemblyAn electronic component is composed of electronic components and has a clear function. 3.8.7 Electronic component The smallest physical entity that conducts electricity by electrons or holes in semiconductors, gases or vacuum. 3.8.8 Indicating device A set of components in a weighing instrument that displays the value of a weighing result in mass units; for a loading weighing instrument, as long as the purpose is clear, it can indicate the mass value of the load or the difference between the mass value of the load and a preset value. 3.8.9 Zero-setting device A device that adjusts the indication to zero when the weighing instrument is unloaded. 209
QB/T 2501—-2000
non-automatic zero-setting device 3.8.9.1 Non-automatic zero-setting device
A device that adjusts the indicating device to zero by operation. 3.8.9.2 Semi-automatic zero-setting device A device that automatically adjusts the indicating device to zero after a manual instruction is given. 3.8.9.3 Automatic zero-setting device device which automatically adjusts the indicating device to zero without any operator intervention. 3.8.10 Tare device device which adjusts the indication to zero when there is a load on the load carrier of the instrument. - does not change the net weighing range (adding a tare device); reduces the net weighing range (subtracting a tare device). 3.9 metrological characteristics 3.9.1 scale interval (d) is the difference in mass units between: - the values ​​of two adjacent scale lines in an analogue indication - the values ​​of two adjacent indications in a digital indication. 3.9.2 reference particle mass of a product the mass of which is equal to the average of the ten largest elementary particles or flakes taken from one or more loads. 3.9.3 preset value the nominal value of a specified charge, expressed in mass units, preset by the operator with the aid of a charge setting device. 3.9.4 static set point the value of the test weight or mass at which the device indicates the selected value for the balanced charge in a static test. 3.9.5 weighing cycle
operation comprising:
- delivery of material to the load carrier.
weighing operation.
- unloading of a single separate load.
3.9.6 final time
the time required to complete the final delivery of material to the load carrier. 3.9.7 minimum capacity (min) the minimum separate load that can be automatically weighed on the load carrier. 3.9.8 maximum capacity (max) the maximum separate load that can be automatically weighed on the load carrier. 3.9.9 reduction ratio (R) the reduction ratio R of the load transfer device is: bzxz.net
where: FM is the force acting on the load measuring device; Fi is the force acting on the load carrier.
3.9.10 Warm-up time
The time from when the charging instrument is powered on until it can operate normally. 3.9.11 Average number of loads per fill (1)
Half the sum of the maximum and minimum number of loads per fill set by the operator; or when the number of loads per fill is not determined directly by the operator from time to time, the average value of the actual number of loads per fill (if known) during normal operation; or the optimum number of loads per fill specified by the manufacturer for the material being weighed.
QB/T 2501—2000
3.9.12 Rated minimum fill The rated value of the fill. Below this value, the weighing result may exceed the allowable error specified in this standard. 3.9.13 Minimum discharge The minimum load allowed to be discharged from the decrementing instrument. 3.10 Indications and errors 3.10.1 Methods of indication 3.10.1.1 Balancing by weightion Balancing the load with a specified weight (taking into account the reduction ratio of the load). 3.10.1.2 Analogue indication Indication of the equilibrium position determined as a fraction of the scale value. 3.10.1.3 Digital indication Indication where the scale markings consist of numbers arranged in sequence and cannot be subdivided into fractions of the scale value. 3.10.2 Errors
3.10.2.1 Error of indication The difference between the indication of a filling instrument and the agreed true value of the mass. 3.10.2.2 Intrinsic error Error of a filling instrument under reference conditions. 3.10.2.3 Initial intrinsic error Intrinsic error The intrinsic error of a filling instrument determined prior to performance tests and span stability tests. 3.10.2.4 Interference error fault
The difference between the indication error and the inherent error.
Note: Interference error is mainly the result of electronic instruments containing or undergoing undesired data changes. 3.10.2.5 Significant interference error significant fault Interference error greater than 0.25 times the maximum allowable deviation of each load tested in use (see 5.1.2) when the load is equal to the rated minimum load. The following exceptions apply: Interference errors caused by various reasons that are generated simultaneously and independently of each other within the charging instrument. When an interference error occurs, the charging instrument cannot perform any operation. - When an interference error occurs, an alarm can be given.
- A transient interference error in the indication that changes instantaneously and will not be misinterpreted as a measurement result. Note: For charging instruments where the load may be more than one load, the integral value of the significant interference error applicable to each static load test should be calculated according to the corresponding test method.
3.10.2.6 Span stability The ability of a filling instrument to maintain the difference between the indication at maximum capacity and at zero within specified limits over a specified period of use.
3.10.2.7 Rounding error of digital indication The difference between the digital indication and the analogue indication assumed to be given by the filling instrument. 3.10.3 Reference value for accuracy class The accuracy class determined by static tests of the weighing unit during the influence quantity tests in the type approval stage. The reference accuracy class is the best accuracy class for the verification of a filling instrument. 3.11 Influences and reference conditions Quantities which are not measured quantities but which have an influence on the measured value and the indication of a filling instrument. 3.11.1 influence quantity211
QB/T 2501--2000
a quantity that is not a measured quantity but has an influence on the measured value and the indication of a charging scale. 3.11.1.1 influence factorinfluence factorA type of influence quantity whose value is within the rated operating conditions specified for a charging scale. 3.11.1.2 disturbance
A type of influence quantity whose variation range is within the limits specified in this standard but exceeds the rated operating conditions of a charging scale. 3.11.2 ratedoperating conditionsoperating conditions giving the range of the influence quantity so that the metrological characteristics of a charging scale are within the maximum tolerances specified in this standard. 3.11.3 reference conditionsreference conditionsA set of values ​​of influence factors specified to ensure that weighing results can be effectively compared with each other. 3.12 tests
3.12.1 material testmaterial testA test of a charging scale with actual or simulated material. 3.12.2 Simulation test Simulation test A test to simulate any part of the weighing operation on the whole charging scale or on the parts of the charging scale. 3.12.3 Performance test A test to check whether the charging scale can achieve its intended function. 3.12.4 Span stability test A test to check whether the charging scale can maintain its performance characteristics after a certain period of use. 4 Classification
4.1 Model
Compiled according to QB1563.
4.2 Specification
Expressed with the maximum weighing value in kilograms (kg) or tons (t). Among them: the maximum weighing value not greater than 1000 kilograms (kg) is expressed in grams (kg), and the maximum weighing value greater than 100α kilograms (kg) is expressed in tons (t). The preferred series of maximum weighing values ​​is 1×10″, 2×10″, 5×10″, where n is a positive integer, a negative integer or zero. 5 Requirements
5.1 Metrological requirements
5.1.1 Accuracy class
The reference accuracy class and accuracy class shall be as specified in 5.1.2 and marked on the charging instrument as specified in 8.1. The accuracy class shall be specified for the expected conditions of use, including the nature of the material to be weighed, the type of installation, the amount of charge and the charging rate.
Note: The accuracy class range for certain applications may be specified by national regulations. 5.1.2 Tolerance range
5.1.2. 1 Maximum permissible error (mpe) of static test The reference accuracy grade ref(x) is only applicable to static test. The maximum permissible error of the shadow factor test is the value specified in 5.1.4 multiplied by the grade designation factor ().
5.1.2.2 Maximum permissible deviation (mpd) of each charge The charging instrument shall have a specified accuracy grade X(). The maximum permissible deviation of each charge from the mean value shall be the range value specified in Table 1 multiplied by the grade designation factor (α). (r) shall be 1×10°, 2×105×10*, and the exponent k shall be a positive, negative integer or zero. 212
Mass value of charge M,g
50
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.