Crane Scales and Heavy Weighing Equipment

Which crane scales / hanging scales are the best suited for your application? As a customer, you can always call the PCE Instruments technical consulting hotline: +44 (0) 2380 987 035 for PCE Instruments UK or +1 (561) 320-9162 for PCE Americas Inc. The colleagues will ask you specific questions about your application and suggest the best crane scales for the solution of your measuring tasks. Below you will also find some tips that should be taken into account when selecting or buying crane scales / hanging scales.

Criteria for selecting crane scales / hanging scales

- weighing range

- resolution / readability

- verification / calibration

- remote display and data transmission

- follow-up costs

- service / support

Weighing range

The maximum weighing range is probably the first and most important question which has to be answered before buying crane scales / hanging scales. This is one of the parameters by which it is possible to determine immediately whether the selected measuring system is suitable for the particular application. The weighing range for crane scales / hanging scales should be bigger than the estimated maximum load. It is ideal, of course, if the maximum load can be estimated up to a few kilograms. A few hundred, could lead to the excess of the weighing range. If, for example, there is a weighing task for an object that weighs about 560kg, a 600kg crane scale can, of course, suffice. Concerning the crane scales’ durability and eventual tolerances, it would be more appropriate to choose a crane scale up to 1000kg. Thus, the bigger the difference between the mass and maximum load is, the less the crane scales will be loaded, which increases the durability.

Resolution / readability of your crane scales

The resolution and readability of crane scales is in most cases dependent on the weighing range. For a weighing range of 1500 kg, a typical value for a resolution would be 0.5 kg. Usually, the resolution can be calculated on the basis of the crane scales’ weighing range. This is mostly a three-thousandth of the crane scales’ weighing range. However, PCE Instruments can offer an even better resolution for certain crane scales / hanging scales. Should the usual resolution steps not be enough for you, you are welcome to contact our technicians.

Verification / calibration of your crane scales

What is the difference between verification and calibration? In both cases, a setpoint is compared to an actual value. However, whereas verification can only be carried out by the verification authority, the calibration of your crane scales can also be performed by laboratories and other institutions. A verified system, for example, cannot be easily adjusted, since these options are blocked by the verification and the verification seal for the purpose of consumer protection. Verification of crane scales is required, for example, for price calculation on the basis of a weight. Calibration of crane scales, on the other hand, is necessary for certification in compliance with ISO 9001. A detailed explanation can be found on our Youtube channel under the name "What is calibration and what differences are there? | PCE Instruments ".

Remote display and data transmission

For most applications a crane scale does not need more than the integrated display. However, it may happen that you have a load that obscures the visibility or needs to be lifted up. Because of that, even though you determine a value with your crane scales, you will never know it. That is why, for some weighing devices an additional remote indicator can be used. This is available, for example, in some models of linkloads or in the PCE-MCWNT crane scales. Via some remote indicators it is also possible to save the weights determined by the crane scales or transfer them directly from the crane scales to a computer. This would give you the opportunity to get an electronic documentation. If you need this function, make sure the systems are equipped with an infrared or radio interface. These can then be used for the wireless transmission of your crane scales’ weighing data.

Crane scales follow-up costs

In principle, maintenance is required for each measuring system. However, the biggest costs for crane scales are calibration, which is recommended annually, as well as verification which has to be renewed every two to three years. The costs are then dependent on the weighing range and accuracy of the crane scales. The calibration of your crane scales, for example, could be specified in your ISO quality manual. Adjustments to calibrations or consumables such as batteries or battery packs for your crane scales must also be considered.

Crane scales service / support

A point to be considered. Of course, you cannot easily assess the performance of a company from the outside. Finally, you have to ask yourself whether you can still receive support or order spare parts for your crane scales in a few years. Call PCE Instruments, speak to one of the technicians and the colleagues from the order department, check yourself the quality of the consultation and rely upon the worldwide corporate network of PCE Instruments (since 1999)..

Below, you can see two common practical applications of crane scales in industry. At the crane scales link, you will be able to see other images of the industrial use of crane scales. You can also get ISO calibration certificates for our crane scales.

Here are some further details of our crane scales with a weight range from 100 kg up to 200,000 kg.

These crane scales are often recommended in the loading ramp area, where the weight of the load can be read directly. However, these crane scales are also commonly used in the production field. For instance; to elevate a drum, and to read the weight to see the results directly at the production site.

The images above show crane scales during application. On the left you can take a look at the PCE-CS HD series crane scales being used in a galvanized installation. As you can see the crane scales are hard to reach in this particular situation, but the infrared remote control allows a comfortable and safe operation from a distance from the crane scales. The picture on the right shows the PCE-CS 1000 series crane scales during operation. Due to its large illuminated LED display, the values measured by the crane scales can be read even when standing far away. This improves the safety at work when weighing out heavy loads, using crane scales.

How accurate is your test equipment? Crane scales need to be verified when they are used to determine the price of a product according to its weight.

Verification certificate for crane scales be performed by the local authorized specialist, or by associates of PCE Instruments. Once an official crane scales verification is done, the crane scales cannot be recalibrated using an external calibration weight. The first verification of your crane scales is valid for two years, but every other verification is valid for one year and must be done annually. We recommend the companies that wish to make an internal quality control to their crane scales to recalibrate them annually or to obtain an ISO calibration certificate.

If you wish to get more information regarding the verification of crane scales or if you need your crane scales to be verified, contact your local authorized calibration verification specialist. If you have any questions, you can get a consultation regarding crane scales from one of our engineers or technicians.

In order to meet the ISO 9000 standard, a crane scales’ certificate consists of a laboratory calibration and a certificate with the testing results of the crane scales. In the certificate there will be the name of the company or the details of the customer.

If you want to use your crane scales under tough industrial conditions, you should make sure that the crane scales’ material is adequate. In some cases it is more important that the crane scales’ material is resilient, in other cases a low weight is much more important. Some of PCE Instruments’ crane scales are (partly) made of stainless steel, other crane scales are made of ABS plastic, high-strength composite plastic or (cast) aluminium.

In addition to the weighing function, some of PCE Instruments’ crane scales also have some other useful functions like an Auto Power Off function, a Peak Hold function, a conversion function, an animal weighing function, a summing function, a zero function, a tare function, etc.

A bottom block is the component on hoists with several rope strands at which the ropes or chains are redirected from their lowest point back upwards. The hook for taking up the load is also attached to the lower block. The lower weighing block is a lower block with the integrated scales. As these scales are usually arranged between the return rollers to save space, the lifting height can be used to the maximum – unlike with separately attached crane scales.

The scales integrated in the weighing block are subjected to tensile stress by the suspended load, i.e. these are the tension scales. Since they are only used for the suspended loads and usually on cranes, it can also be called the suspended scales or the crane scales. When deciding on the weighing block, it is essential to check whether the calibrated scales are required for the intended weighing operations. If so, only models that are legal for trade may be chosen. The verifiable crane scales must then be calibrated or conformity-assessed for the planned place of use before delivery. For this purpose, since the measuring result of these scales depends on the gravitational force at the place of use, the postcode and the name of the place of installation are requested from the person ordering the scales.

The weighing block can be used instead of the additional crane scales for both overhead travelling cranes and slewing cranes with wire rope hoists. Due to its design, it ensures a stable position of the load hook and thus a smooth lifting of the load. By integrating the scales into the crane bottom block, the number of the parts subjected to the tensile stress is reduced and the lifting height of the hoist is not restricted by the scales and its suspension and hook as is the case with the attached crane scales.

The compound scales or combined crane scales consist of several crane scales or weighing blocks. Very long or bulky parts are best weighed by suspending them on several separate crane scales or weighing blocks. If these individual scales can communicate with each other, it is possible for the crane scales to display not only the partial weight it determines, but also the total weight for the item being weighed. These crane scales in the scales network is called the master, the others that send to it are called slaves. Another way to display the total weight from the weighings of several scales is to send the weighing data from each crane scales to a separate weighing indicator, which can sum up the individual values.

The model types of the weighing block are usually designed in such a way that the attached materials may not only be weighed but also transported. For many loading processes where weighing is required, this is a considerable advantage over simple crane scales where the load may only be lifted but not transported.

Lifters are aids for lifting loads. According to their use, they can be divided into personal lifters and material lifters. For both applications, the devices can be supplemented with the lifter scales. The lifter scales are often the hanging scales that are suitable for use on a specific type of the lifter or on different lifters. These lifter scales must be calibrated or conformity assessed for specific applications.

Like the lift truck scales, the lifter scales can be used to weigh material during the transfer process. Since the total weight is displayed almost immediately after the load is picked up, it is possible to prevent the warehouse floors or vehicles from being overloaded or the incorrect quantities from being delivered. If too high or too low weights are detected when loading the material lifter with several elements, this can be corrected immediately by removing partial quantities or loading additional elements. The combination of lifting and transport equipment with the scales simplifies many processes and increases the safety of storage and transport processes. If goods are weighed in the course of commercial transactions where the price is determined on the basis of the weight, the lifter scales used must be calibrated.

Personnel lifters are mainly used for moving or transporting persons with limited mobility. Since the weight of these persons can seldom be determined with conventional personal scales, the lifter scales are often used for this purpose. In most cases, the lifter scales can be mounted on the lift and removed again relatively easily. This makes it possible to easily move the lifter scales from one lifter to another, for example when people need to be weighed on another ward or in another building. In this way, the number of lifter scales to be kept available in a hospital or care facility can be kept small. The lifter scales can also be used in home care when the lifter is available to move the patient. If the weight is determined for diagnostic or therapeutic purposes, the lifter scales used for this purpose must be calibrated. In addition, it is subject to the Medical Devices Act for these applications.

What is unusable waste for somebody can still be used as a valuable raw material by the others. Rubbish or waste are materials that are sorted out and given away by the owner because he no longer needs them. Some of the waste from industry, commerce and households, however, can be easily reused or thermally recycled. Others, such as radioactive materials, explosive materials or toxic hazardous waste, cannot currently be reused with reasonable effort. Instead, in order to avoid risks, they have to be stored at great expense or rendered harmless.

For many types of waste, the quantities are registered by weight. Weighing with crane scales can be easily integrated into loading or unloading processes. For example, on trucks with a loading crane, waste can be weighed with the crane scales immediately upon collection or delivery and the weight can be documented. The crane scales with remote control and remote display are often used on bridge or gantry cranes that move large-sized elements in halls or storage areas.

Depending on the recyclability of the waste, either allowances are paid or disposal fees are charged at the time of delivery or collection. Often the prices are set according to weight. In these cases, the verified scales must be used to determine the invoice amount. For this reason, the disposal and recycling companies usually have stationary vehicle scales embedded in the ground that are regularly verified. Complete vehicles with and without loads are weighed on these scales. In addition, the verified crane scales or platform scales must be available for the correct weighing of smaller quantities.

Residual materials that are collected by type and recycled replace scarce raw materials. For decades, waste paper, rags, waste glass and scrap metal have been industrially recycled. This not only reduces the amount of waste, but also lowers the demand for resources and energy for the manufacture of new products. The companies that use secondary raw materials must determine their weight not only for calculating the purchase price. Knowing the available weight is also important for storage and use in production.

In the processing industry, cranes are often used for the internal transport of materials. There, it often makes sense to use the crane scales to determine the weight. Since these in-house weighings are not subject to verification, the unverified crane scales can be used here, unlike when purchasing the raw materials. Waste paper bales, big packs or transport containers with sorted broken glass or scrap metal can be easily lifted and weighed with suitable hooks and slings. If the quantity contained in open containers does not fit, the material can be removed or added during weighing until the crane scales indicate the desired weight.

A tension measuring strap can also be used like crane scales with the right shackles and hooks. It differs from conventional crane scales primarily in its design and the additional application options when determining tensile forces.

Characteristic shape of the tension strap
While the usual crane scales usually have a very compact shape, the tension measuring strap, as the name suggests, is usually flat and elongated. A circular opening for attaching the load bearing elements is arranged centrally on each of the two longitudinal sides of this strap. The same hooks and shackles can be attached there as with the normal crane scales with the same load capacity. However, it is also possible to do without hooks and shackles for certain measurements and to pull the ropes or similar elements directly through the openings of the measuring strap.

Operation and functions of the tension measuring strap and crane scales
Many models with remote control are available for both the crane scales and the tension measuring strap. In contrast to the remote control of the crane scales, the separate control panel of the tension measuring strap is usually equipped with a display. Via this handheld device it is often possible to call up the functions that are not accessible via the control panel on the measuring cell. These special functions on the remote control include, for example, parameter settings, the storage of the measured values or the transmission of the measured data via an interface.

In addition to the standard crane scales and tension measuring strap functions such as ZERO, TARA and UNIT for selecting different mass or force units, many models also offer summation and percentage functions. The storage of the PEAK value is one of the standard functions for the tension measuring strap, since the peak value is of particular interest in force measurements. In the case of the crane scales, there are also models with a PEAK function that are suitable for tensile tests, but there are also many that do not offer this function.

Heavy-duty load cells designed for tensile loads are used in crane scales. Safety is a top priority, especially with heavy loads and when moving the load. This is especially true when the failure of components of the crane scales can endanger people. This is not only about the risk of injury during weighing. Incorrect weighing results after damage to the heavy-duty load cell can lead, among other things, to incorrect dosing of raw materials or incorrect loading of transport equipment and, as a result, to accidents.

To minimize the hazards, many models of the crane scales are equipped with overload protection devices. The safety factor related to overload is often 4 : 1 or even 5 : 1 for the crane scales, which means that there is no risk of breakage for the load-bearing components of the crane scales until four or five times the maximum load is exceeded. The weighing process is therefore safe even if the load excess is high. However, the heavy-duty load cell will be damaged if the load excess is of such a high degree. In most cases, the load cells can only tolerate the loads about ten to thirty percent above the maximum load without being damaged. This value is specified as the limit load for the load cell or for the crane scales.

Regardless of the measuring principle used, the heavy load cell is generally the most sensitive component of the digital crane scales. It can be affected not only by loading with too much weight, but also by lateral or too fast load application, electrical overvoltages or moisture. Total failure of the load cell does not always occur immediately. The damage may also be indicated by unstable or unreliable readings or by the zero point being shifted. Defective load cells usually have to be replaced by the new ones.

By inspecting the damaged crane scales, the cause of the failure can almost always be determined. In certain applications, it is not possible to eliminate the causes of damage, for example, increased humidity levels or variable electromagnetic fields in the environment. In these areas, the crane scales that are insensitive to these stresses should be used. If the crane scales is to be used outdoors or in the rooms where there is high humidity, the models with IP67 protection rating are recommended. With these, the housing is so tight that moisture and foreign substances cannot reach the heavy-duty load cell.