The electronic hanging scale is an electronic weighing instrument that measures the weight of an object when it is suspended. It can also be called hook scale, hanging scale, hanging scale and hook scale. It is generally used in fields such as steel, metallurgy, factories and mines, freight stations, logistics, fair trade and workshops that need loading, unloading, transportation, measurement and settlement.
The electronic hanging scale is mainly composed of electronic components – load cell and circuit. The circuit also includes amplification circuit, AD conversion circuit, single chip microcomputer circuit, display circuit, keyboard circuit, communication interface circuit, regulated power supply circuit, etc. Its working principle is that when the load acts on the sensor through the hook, the elastomer of the sensor will change slightly, so as to change the resistance value of the resistance strain gauge attached to the elastomer and change the balance of the bridge. The output voltage is changed, and the changed voltage signal is converted into a digital signal through a high-speed and high-precision A / D converter, The wireless transmitter (or wired cable) is transmitted to the secondary instrument. The secondary instrument calibrates the obtained signal, sends the corresponding weight value to the display screen for display, and can also be printed by a printer. If necessary, it can be transmitted to the computer management system.
At present, the electronic Hanging Scale implements the gb11883-89 electronic hanging scale standard. N represents the division number, e represents the division value, and the tolerance is represented by E. There are three accuracy levels:
- OIML class III standard 1000 ＜ n ≤ 10000, with a tolerance of 0.5E ~ 1.5E
- The tolerance of domestic class a standard 1000 ＜ n ≤ 10000 is 1.0e ~ 2.0e
- The tolerance of domestic class B standard 400 ＜ n ≤ 1000 is 1.0e ~ 2.0e
According to different structural characteristics, working forms and working environment, electronic hanging scales can be divided into many types, mainly including the following:
- In terms of structural characteristics, it can be divided into dial hanging scale and electronic hanging scale;
- In terms of working forms, it can be divided into hook head suspension type, traveling crane type, axle seat type and embedded type.
The traveling electronic hanging scale is mainly used in slaughtering meat Union, meat wholesale, storage supermarket, rubber manufacturing, papermaking and other industries to weigh the goods on the hanging track;
The hook head scale is mainly used for weighing large tonnage goods in highly restricted occasions such as metallurgy, steel mills, railways and logistics, such as containers, ladle, molten iron ladle, coil, etc. The hook head hanging hook scale affects the height of goods lifted by the crane; The crane needs to be reconstructed for crane and axle seat hook scales, which will affect the crane operation during maintenance; The embedded hook scale is to install a weighing link at a certain part of the crane, which does not affect the lifting height or crane operation. It is a direction of industry development.
- In terms of reading form, it can be divided into four types: scale body direct display (i.e. integration of sensor and scale body), wired operation box display (crane operation control), large screen display and wireless transmission instrument display (which can be networked with Microcomputer).
Direct display hanging scale, also known as direct view hanging scale, is a scale body direct display hanging scale, that is, the sensor and scale body are integrated, and there is a display screen, which can directly read the weighing data. It is usually powered by the installed battery, so as to eliminate the shackle of the power line. Just put the measured object on the hook, and the weight will be directly displayed on the electronic Hanging Scale in the form of numerical value, which can realize direct measurement and direct reading, which is very convenient. It is applicable to import and export statistics, stock control, weight weighing, etc. in the fields of logistics warehouse, industrial and mining enterprises, processing workshop, fair market, freight station transportation, etc. The direct display hanging scale generally has the functions of automatic accumulation, peeling, long-distance peeling, value holding, display division value, overload limit, under load reminder and low power alarm.
Dial hanging scale is a kind of direct viewing hanging scale, which can be used alone. It is often used for gravity measurement in petroleum, coal field, geological exploration, aquatic fishing, hoisting machinery and other industries. At the same time, it is also used for traction measurement in tractor, automobile transportation, power line erection, construction and other industries. The main models of dial hanging scales are: 5-inch dial, 10-inch dial, 500kg, 1000kg, 2000kg, 4000kg, 5000kg, 10000kg, 20000kg, AP danymeter, AP crane scales, etc.
Wireless hanging scale is generally composed of wireless instrument, scale body, trolley Wireless transmitter (inside the scale), wireless receiver (in the instrument), charger, antenna and battery. Hang the lifting ring of the scale on the hook of the crane. When the object is hung on the hook of the scale, the sensor in the scale deforms under tension, and then the current changes. The changed current is converted into an electrical signal through a / D, and then the transmitter sends the radio signal, and the receiver receives the signal and transmits it to the instrument After the conversion calculation of the instrument, it is finally displayed. They are generally used in harsh environments, such as some mines, docks, etc. to measure some dangerous objects. Through wireless operation, they can stay away from these products, so as to avoid harm to human body. Wireless hanging scale generally has the characteristics of automatic measurement, energy-saving operation, remote operation, peeling, accumulation, cumulative display, backlight, data retention, storage, setting printing, query, intelligent control, adjustable division value, adjustable signal frequency, low failure rate, overload alarm, anti cheating, simple maintenance, etc. Different wireless hanging scales can adapt to different use environments.
- In terms of sensor form, it can be divided into resistance strain type, piezomagnetic type, piezoelectric type and capacitance type.
- It can be divided into normal temperature type, high temperature type, low temperature type, anti magnetic insulation type and explosion-proof type in terms of service environment.
The high-temperature electronic hanging scale has a unique sensor dedicated to the hanging scale, and has a good heat insulation treatment on its surface. The installed high-temperature heat insulation board can effectively prevent the high-temperature electronic hanging scale from feeling the radiation of the heat source, so that it can accurately measure the value even in the state of high temperature. The 24 bit high-precision ad adopted by the product itself can achieve the stability and accuracy of measurement, and will automatically alarm in the process of overload; It can realize wireless remote control, reset zero design, query, shutdown and other functions within a fixed distance. It is widely used in the high-temperature environment of some iron and steel industries.
The anti magnetic and anti heat hanging scale has the advantages of accurate weighing, rich functions, simple operation, various configurations and excellent anti magnetic and anti heat performance. It is widely used for weighing and metering in high-temperature, strong magnetic and multi dust environments such as steel rolling, smelting, aluminum ladle, molten steel ladle, electrolytic aluminum, electrolytic copper, electromagnetic suction cup crane and electric furnace ironmaking;
Explosion proof electronic hanging scale can be used in hazardous gas or dust occasions, such as coating, paint, pharmaceutical, petrochemical, military and other industries;
- In terms of data stabilization processing, it can be divided into static type, quasi dynamic type and dynamic type. At present, the commonly used are static and quasi dynamic, and the dynamic is still in the research and development stage.
Generally speaking, at present, the high-temperature hanging scales, direct display hanging scales and wireless hanging scales are widely used in the market. They are often used in high-temperature environment, warehouses and docks with dense commodities and the measurement of hazardous objects. No matter which type of electronic hanging scales, they have made corresponding special treatment for electronic hanging scales due to the particularity of their environment, The utility model has the advantages of accurate measurement, simple operation and safe use.
Compared with other scales, the electronic hanging scale has the following advantages:
(1) reduce the operation links, speed up the measurement speed, save manpower, material resources and time, and complete the measurement of goods in the process of lifting and loading and unloading.
(2) it does not occupy the site and is convenient and flexible to use.
(3) it can make the measurement work continuous and play the role of monitoring and control. For example, in electrolytic workshops and metallurgical casting occasions in non-ferrous industry, the weight of aluminum (steel) water in aluminum (steel) water ladle can be monitored in time to achieve the purpose of large utilization of equipment and energy saving.
(4) realize remote transmission of measurement data and centralized monitoring to make people leave the harsh and dangerous working environment.
(5) it is easy to combine with the crane control system to reduce the post setting. The newly developed electronic hanging scale of multifunctional crane unit suitable for electrolytic aluminum workshop is organically combined with the crane remote control.
(6) convenient measurement verification and simple error correction.
(7) multi function, high precision, strong anti cheating and low maintenance cost.
At present, there are many electronic scale manufacturers at home and abroad. The product forms and prices are uneven, and there are many differences in functions. Therefore, when selecting the electronic hanging scale, we should start from the aspects of product measurement performance, interoperability and practicability according to the actual needs of specific use and in combination with the manufacturer’s product sample book, Special requirements (explosion-proof, high temperature resistance, etc.) need to be specified when ordering.
- Measurement performance: as a measuring instrument, the primary problem is accuracy. Therefore, when selecting a hanging scale, we should first consider whether the accuracy can meet the actual work requirements and national standards. Generally speaking, it is OK to meet the accuracy of the actual work requirements, and there is no need to pursue too high accuracy, The working state requirements, maintenance requirements and price of electronic hanging scale with high precision are relatively high.
- Interoperability: there is usually more than one electronic hanging scale or other weighing apparatus used by a unit, and the interoperability of products and accessories is very important. If the networking management can be realized, it can greatly facilitate users and reduce the maintenance cost;
- Practicability: when considering the weighing range, it is easiest to ignore the minimum range. When the hanging scale with too large range is used for small weighing, the relative error will become larger. In addition, it is also necessary to consider the supporting problems such as hanging scales and cranes, and whether the lifting rings and hooks are appropriate. At the same time, we should also consider whether the electronic scale accessories and consumable materials are universal, whether they are guaranteed for a long time, etc.