GB/T 31890-2015Electronic screw weigher (English PDF)

Foreword

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

This standard is redrafted and modified in relation to the International Recommendation

of OIML R50-1 "Continuous totalizing automatic weighing instruments (belt weighers)

- Part 1.Metrological and technical requirements - Tests" (1997E).

Since the current management mode of measuring products in China is different from

the international ones, this standard has more adjustments in structure compared with

R50 International Recommendations. For the convenience of comparison, a

comparative list of the clauses of this standard to the clauses of International

Recommendation is given in informative appendix A.

Due to the legal requirements of China and the special needs of the industry, this

standard has been modified when international recommendations are adopted. These

technical differences are indicated by a single vertical line in the margin of the clause

to which they refer. A list of technical differences and their reasons is given in Appendix

B for reference.

This standard is proposed by China National Light Industry Council.

This standard shall be under the jurisdiction of China Weighing Instrument

Standardization Technical Committee (SAC/TC97).

Drafting organizations of this standard. Saimo Electric Co., Ltd., Jiangsu Institute of

Metrology, Nanjing San'ai Industrial Control Co., Ltd., Tongling City SSS Electronics

Co., Ltd.

1 Scope

This standard specifies the terms, product models, requirements, test methods,

inspection rules, marking, packaging, transportation, and storage of electronic screw

weighers (also known as screw reamer scales, screw feeder scales, hereinafter referred

to as "screw weighers").

2 Normative references

The following documents are essential to the application of this document. For the dated

documents, only the versions with the dates indicated are applicable to this document;

for the undated documents, only the latest version (including all the amendments) is

applicable to this standard.

GB/T 191 Packaging - Pictorial marking for handling of goods (GB/T 191-2008,

ISO 780.1997, MOD)

3 Terms and definitions

The terms and definitions defined in GB/T 14250-2008 and the followings apply to this

document.

The intrinsic error of a screw weigher that is determined before the performance test

and durability test.

4 Product model

It shall be compiled according to GB/T 26389-2011.

5 Metrological requirements

In the temperature range of -10 °C~+40 °C, the screw weigher shall meet the

corresponding metrological requirements and technical requirements.

6 Technical requirements

For a screw weigher, there shall be no accidental failure or control component

maladjustment that is not obvious and may interfere with the metrological performance

and normal function of the screw weigher.

7 Test methods

It shall be kept free of moisture condensation on the weighing unit of the screw weigher

under test.

The electrostatic discharge test shall be carried out according to GB/T 17626.2, and the

test level shall be level 3.

8 Inspection rules

For type inspection, 1 test prototype shall be randomly selected from the qualified

products, and the sampling base shall not be less than 3.

The initial inspection of a screw weigher shall be carried out after the on-site installation

is completed, and the in-service inspection shall be carried out regularly according to

its use requirements.

9 Marking, packaging, transportation, and storage

Under normal conditions of use, descriptive signs shall be firm and reliable, have a

uniform size and shape, and be clear and legible.

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