Buying advice for crane scales in our ESSMANN scales store
Crane scales are mainly used in industry to measure large masses. They are usually hung on the hook of a crane and the goods to be weighed are attached to the lower hook or shackle of the scale. Hooks and shackles are available in different designs as required. Crane scales are often used in production facilities to weigh raw materials.
Crane scales are also used in warehouses and distribution centers to determine the weight of goods. In ports and transshipment centers, the mass of goods can be determined directly when unloading a ship. When loading container ships, each container is weighed with the crane scale and placed in the ship according to its weight to ensure even distribution of the freight.
The weighing ranges that can be recorded with crane scales range from a few hundred kilograms to 100 tons, depending on the maximum load limit and resolution of the scale.
It is important to choose the right crane scale for your specific needs. We have listed what you should consider before buying in the box below.
What to consider when buying crane scales
- Type of crane scale
There are different types of crane scales, such as simple hanging scales, digital crane scales with remote control, mechanical scales for weights from 200 to 85,000 kg, calibrated crane scales and pointer crane scales. The choice depends on your specific requirements. - Weighing range and resolution
Select a weighing range that does not exceed 2/3 of the maximum permissible nominal load of the crane scale. Crane scales are normally dimensioned larger (150% nominal load), but unexpected forces can occur when the crane moves, which can overload the load cell.
The weighing range directly influences the display accuracy, also referred to as graduation or resolution. For a weighing range of up to 6,000 kg, the resolution is 1,000 g. A crane scale with a maximum load of 3,000 kg displays an accuracy of 500 g. The crane scale should therefore be selected according to the loads to be weighed. - Safety
The crane scale is used to suspend the load to be weighed and then lifted by the crane. As a load handling device, it is subject to Directive 2006/42/EC:2019-06-20. In some companies, the load to be weighed is also moved from one place to another. If the scales or parts of them are defective and can cause the load to fall, this can have serious consequences. To avoid damage caused by using the crane scale as a load handling device, operators must be trained and the scale must be checked regularly. The operating instructions specify the intervals for checking the scale. The above-mentioned guideline limits the service life of a crane scale, depending on the load cycles. Further information can be found in the respective operating instructions. - IP protection class and temperature range
Crane scales are used both indoors and outdoors. When selecting a crane scale, it is important to pay attention to the IP protection class and the operating temperature. If the scale is used outside the permissible temperature range, accuracy can no longer be guaranteed. - Measured value storage and transmission
Our digital crane scales offer functions for storing measured values and more as standard. They enable the creation of totals, the display of maximum values of a measurement series and, if an interface is available, the output of measurement data to a PC, printer or smartphone using the EWP scales software. Remote controls are also included in the scope of delivery, which simplify operation and speed up the weighing process. - Calibration
According to EU Directive 90/384 EEC, hanging or crane scales must be calibrated in certain applications. calibrated e.g. in commercial transactions when the price of a product is determined by weighing. - Dead weight and battery life
Many digital crane scales are lightweight and can therefore be moved quickly by one person. If the scale is to be moved frequently, the tare weight of the crane scale should be taken into account during the selection phase. For mobile use, another relevant criterion is the battery life or the possibility of changing the battery. - Manufacturer and price
Compare prices and quality of different manufacturers before making a decision. - Accessories
Think about which accessories you may need, such as a rotating hook or a remote indicator for longer distances.
How do digital crane scales and hanging scales work?
Crane scales use the tensile effect to determine the weight. Most crane scales use an S-shaped load cell to measure tensile and compressive forces. To determine a weight, it is suspended from the digital crane scale and secured with a snap hook. The applied force deforms the crane scale’s stable spring balancer in a linear fashion.
After the weight has been removed, the spring balancer returns to its starting position. The digital display of the crane scale continuously shows the measurement result. Operation is carried out directly on the crane scale, via remote control or connected weighing software. It is also possible to carry out tensile force measurements. With optional remote displays, the measurement result can also be read from a distance.
Compared to platform or floor scales, a crane scale does not require a fixed installation surface. They are very mobile and can be quickly moved or swiveled to another position using a crane. Even long and bulky goods can be weighed by using suitable load handling equipment such as ropes, chains or crossbeams.
For particularly large or sensitive goods, where several load application points are required for transportation and fast and reliable weight determination, several crane scales can be interconnected to form a network. The weights of the individual load application points are added together, similar to axle load scales with several platforms.
The application areas of crane scales
Crane scales are ideal for weighing loads that can be suspended. They are used in various areas where goods are transported and handled by crane. These include transport and logistics companies, steelworks, foundries, recycling yards, chemical companies, the textile, plastics and paper industries, metal processing companies, mechanical engineering and the steel trade.
When a crane is used for loading or unloading, a crane scale can immediately check and record the weight of the load. This weight information is useful for complying with maximum weights, distributing the weight evenly on the means of transport or optimizing storage in pallet racks or cantilever racks. The recorded weight data can be used directly during loading or unloading to create freight documents and manage stock levels.
Crane scales are also suitable in areas where there are high requirements for cleanliness or explosion protection, such as in aerospace technology, clean rooms or explosion-protected areas.
Maintenance, calibration and verification
The reliable operation of your crane scales in day-to-day business creates a high level of availability and thus supports the success of your company. Most of these scales are used for internal use and are therefore not calibrated and usually cannot be verified. Due to the dynamic and high load, regular calibration and maintenance is recommended. This prevents incorrect measurements and accidents.
Calibration of a crane scale
A crane scale is calibrated with test weights. To do this, the test weights are attached to the crane scale and the measured value is read off. If the displayed value deviates from the weight value of the test weight, the scale must be adjusted. This is possible with many of our scales via the device menu, otherwise the scale can also be sent to the manufacturer, who will carry out the adjustment. As this is always also considered a load handling device, the operating time is limited due to the dynamic load. The operating time can be found in the operating manual or can of course be requested.
Calibrated crane scale
If the calibrated crane scale is used in legal metrology, for example for price determination, regular recalibration is required. The verification periods are based on the German Measurement and Verification Ordinance. The applicable intervals for recalibration depend on the maximum weighing range:
- Crane scale calibrated up to 3t / crane scale 3000 kg: Every 2 years
- Crane scale calibrated from 3t / crane scale 3000 kg: Every 3 years
The marking of measuring devices has been revised. The beginning and no longer the end of the calibration period is now marked. The end of the calibration period can be read on an optional additional sign.
(© Arbeitsgemeinschaft Mess- und Eichwesen)
(© Arbeitsgemeinschaft Mess- und Eichwesen)
Crane scales that have been placed on the market with conformity assessment, also known colloquially as manufacturer verification the verification period begins when they are placed on the market.
Example crane scale 1t with a calibration period of 2 years:
As not all crane scales can be verified, it is essential to clarify whether verification is required before making a selection. When ordering a calibrated crane scale, the zip code and the location where it is to be used must be specified, as the gravity value influences the weighing result.
Let us advise you
ESSMANN | Waagen & Automation has decades of experience in handling crane scales. We have our own workshop and a team of service technicians to offer you a fast and efficient service for maintenance and repairs. This minimizes downtime and extends the service life of your crane scales.
We are familiar with the specific requirements and regulations in various areas of application and train your employees in these topics, as well as in the proper use of the scales.
With us, you always have a contact person who can offer you support if required.
Scale builder tip:
ESSMANN online store
If you already know what kind of crane scale you need, visit our online scale store. Here you will find a large selection of configurable crane scales and hanging scales.
