With the official promulgation of International Recommendation R87-2004 "Net Content of Prepackaged Commodities", OIML TC9/SC2 Working Group in 2004 also proposed a revised draft of OIMLR51 "Automatic Weight Separation Scale", as one of the 24 official member states of OIML, China Weighing and Measuring Technology Committee will be timely feedback of China's modifications to the OIML.OIML Working Group summarized the comments of member states and formed a 4CD draft in early 2005 for adoption by the International Conference on Weights and Measures. The OIML working group summarized the opinions of member states and then formed a 4CD draft in early 2005 for the International Conference on Weights and Measures (ICWM) to vote on and adopt. China has also revised R87-2004 to form the "Measures for Supervision and Management of Quantitative Packaging Commodity Measurement" (2005 edition). As a packaging logistics quality inspection line indispensable measurement and testing equipment - an automatic weight sorting (hereinafter referred to as "sorting scales") is an important item in the supervision and management of the measurement of quantitatively packaged goods.

I. Measurement requirements (OIMLR51-2004)

1. Accuracy level

In order to meet the OIMLR87 International Recommendations, "the net weight of prepackaged goods" requirements, prepackaged goods can be divided into four levels of checkweighing sorting scales: XI, XII, XIII, XIII, XIIII each level also includes a manufacturer-specified (x) factor, the value of (x) should be 1x10, 2x10, 5x10, where h is a positive integer, a negative integer or zero.

2. Calibration index value (e)

The calibration index value and the number of calibration indexes

3. Maximum permissible error of automatic operation

(1) the maximum allowable average (system) error, the average (system) error formula: x / n where; x a load indicating a certain time; average error; n weighing times.

(2) level indicator factor (x) = 1 when the maximum allowable standard deviation (random error)

Second, sorting scale selection principles

Combined with the latest series of parametric sorting scale product parameters, talk about how to accurately select the sorting scale.

Selection of sorting scales, the above parameters are the most important:

1. The relationship between the weighing range and accuracy

The larger the weighing specifications (1-50) kg, the worse the accuracy (10g); weighing specifications the smaller (0.6~600) g, the better the accuracy (+0.02g)

2. The measured items of measurement speed, length and accuracy of the relationship is now cited as an example in Table 4 of the CSHO6L type sorting scales, speed, length and accuracy of the relationship.

3. Measurement of the length and width of the belt with the weighing range, sorting accuracy can be seen from Table 4, weighing specifications large (1 ~ 50) kg, sorting accuracy is lower (: 10g); weighing specifications small (0.6 ~ 600) g, sorting accuracy is higher (+0.02g).

Third, the latest developments in sorting scale technology

1. Sorting scale self-adaptation, automatic adjustment, self-diagnosis, remote control operation.

The latest sorting scale products have been developed in the direction of intelligence, for different sizes of inspected items and measurement speed, can automatically determine the most appropriate screening and measurement time; when the ROM/RAM, A/D, photoelectric devices, communication and other abnormalities, there are prompts and take measures to achieve the function of automatic adjustment, self-diagnosis: As the latest weighing conveyor with ARCNET and ETHERNET As the latest weighing conveyor has ARCNET and ETHERNET network communication function, the system can realize centralized control with the computer combination scale of the previous process, as well as remote control operation and process feedback control.

2 weight sorting and gold detection, X-ray foreign body detection integration in recent years, sorting scales products to small, multi-functional direction, metal detection X-ray foreign body detection and sorting of integrated weight sorting scales have been introduced. At present, the general metal detector can detect (0.8-1.0) mm metal foreign body detection speed up to (40 ~ 60) m / min. But the metal detector can not detect such as hair, thread, bone glass and other foreign objects. For this reason, a new X-ray foreign body detector came into being to solve the hair, thread, bone, glass and other foreign body detection problems. The detection speed is up to 65m/min.

3. Weight sorting and packing logistics inspection integration

Recently, the world's industrialized countries have begun to further expand the function of the weight checker to the warehouse box automation management. A set of weight sorting box geometry detection, radio frequency automatic identification coding, image recognition and other technologies such as the shape of an integrated transport inspection equipment has been used in logistics management systems.

4.HACCP technology safety system

HACCP (HazardAnalysisandCriticalControlPoint), "Hazard Analysis and Critical Control Point" system. Currently is the European and American countries, the World Health Organization food production market access requirements of the system. The latest HACCP management system, food safety concepts into the design process, rather than the traditional final product inspection. Certification and Accreditation Administration of China in 2002 issued a "food production enterprises Hazard Analysis and Critical Control Points (HACCP) management system certification regulations," requiring all export food processing enterprises must complete the HACCP certification as soon as possible to obtain the food export "pass". Recently, China's food and beverage industry unprecedented development, the requirements of sorting scales in line with the international HACCP food safety and health system standards of the growing call, which can meet the HACCP requirements of the weight of the sorting scale has also been pushed to the market.

Fourth, the use of sorting scales of economic benefits

As a result of sorting scales is a test machine, the previous production process can be screened out and rejected substandard products, so its economic and social benefits are very substantial. Now the food industry 500g / bottle, 20 bottles / box of filled juice drinks as an example, choose the weighing range of (1 ~ 10) kg CMA10 type sorting scales for sorting. Each bottle of beverage to 3 yuan, assuming that the workers to fill each bottle more than 5, the whole case of 20 bottles of drinks is more than 100g, worth 0.6 yuan. A sorting scale measuring speed of 50 boxes / min, 24,000 boxes / 8h, a year according to 300 days, then 7.2 million boxes / year of production, the light of raw materials can save 4.32 million yuan) year. In addition, due to the use of automatic sorting scales, there is no need to manually move up and down to detect, thus reducing labor intensity and improving production efficiency.

V. Conclusion

Recently, due to the weight checker has gradually entered our country's beverage, dairy, food, medicine and processing and packaging industries, some far-sighted enterprises, especially some of the more sizeable beverage, food production wide family has begun to use the checkweigher. I believe that, with the domestic market sales and management of the increasingly standardized, automatic checkweigher will be as high-speed, highly accurate measurement means more and more favored by manufacturers of various industries.