GB/T 7721-2017Continuous totalizing automatic weighing instruments (belt weigher) (English PDF)

Foreword

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

This standard replaces GB/T 7721-2007 "continuous cumulative automatic weighing (electronic belt scale)". Main compared with GB/T 7721-2007

The technical changes are as follows.

--- Increased the accuracy level of the 0.2 product (see 5.1).

--- Increased the minimum cumulative load requirements (see 5.4).

--- Increased requirements for component protection and seals and preset controls (see 6.3.7).

--- Increased the requirements of the tape correction device (see 6.6).

--- Increased anti-interference test requirements (see 7.1.1).

--- Increased durability test requirements (see 7.1.2).

--- Increased requirements for interfaces, data storage devices, and software (see 7.6, 7.7, 7.8).

This standard uses the redrafted law to amend the International Legal Organization No. 50 International Recommendation OIMLR50.2014(E) "Continuous Accumulation

Automatic weighing instrument (belt scale)" (R50-1, R50-2, R50-3).

This standard has more structural adjustments than OIMLR50.2014(E). This standard and OIMLR50 are listed in Appendix C.

The.2014(E) chapter numbering control list.

There are technical differences between this standard and OIMLR50.2014(E). The terms involved in these differences have passed the margin on the outside of the page.

The vertical single line at the white position is marked, and a list of the corresponding technical differences and their causes is given in Appendix D.

This standard also made the following editorial changes.

--- Appendices A and B of this standard to the second part (R50-2) and third part (R50-3) of the R50 International Recommendation.

1 Scope

This standard stipulates terms, product models, requirements, inspections of belt conveyer type continuous cumulative automatic weighing instruments (hereinafter referred to as "belt scales").

Methods and rules, signs, packaging, transportation and storage.

This standard also provides standardized requirements and test procedures for evaluating the metrological characteristics or technical characteristics of belt weighers in a traceable manner.

form.

This standard applies to.

--- Using the principle of gravity, a continuous weighing method to determine and accumulate the weight of bulk material.

--- Belt weigher used with single speed belt conveyors, variable speed or multi-speed belt conveyors.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article

Pieces. For undated references, the latest version (including all amendments) applies to this document.

GB/T 191 packaging, storage and transportation logo

GB/T 2423.1-2008 Environmental testing for electric and electronic products Part 2. Test methods Test A. Low temperature (IEC 60068-2-

1.2007, IDT)

GB/T 2423.2-2008 Environmental testing for electric and electronic products Part 2. Test methods Test B. High temperature (IEC 60068-2-

2.2007,IDT)

GB/T 2423.3-2016 Environmental testing - Part 2. Test method test Cab. Constant moisture heat test (IEC 60068-2-

78.2001, IDT)

GB/T 2423.4-2008 Environmental testing for electric and electronic products Part 2. Test methods Test Db. Alternating heat test method

Method (IEC 60068-2-30.2005, IDT)

GB/T 2424.1-2015 Environmental test part 3. supporting documents and guidelines for low temperature and high temperature test (IEC 60068-3-1.

2011, IDT)

GB/T 2424.2-2005 Guidelines for Damp Heat Tests for Environmental Testing of Electrical and Electronic Products (IEC 60068-3-4.2001, IDT)

GB/T 2887 Computer Site General Specifications

GB/T 4167 weight

GB/T 4879 rust-proof packaging

GB/T 5048 moisture-proof packaging

GB/T 7551-2008 load cell

GB/T 7724 electronic weighing instrument

GB/T 13384 general technical conditions for mechanical and electrical product packaging

GB 14249.1-1993 Electronic weighing equipment safety requirements

GB/T 14250 weighing terms

GB/T 15395 General Specifications for Electronic Equipment Cabinets

GB/T 17214.2 Working conditions for industrial process measurement and control devices Part 2. Power (IEC 60654-2, IDT)