Hanging Scales

Which hanging scales are the best suited for your application? As a customer, you can always call the PCE Instruments technical consulting hotline: 02903 - 976 99 - 8901. The colleagues will ask you specific questions about your application and suggest the best products for the solution of your measuring tasks. Below you will also find some tips that should be taken into account when selecting or buying hanging scales.

Criteria for selecting 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 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 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 560 kg, a 600 kg hanging scales can, of course, suffice. Concerning the durability and eventual tolerances, it would be more appropriate to choose a hanging scales up to 1,000 kg. Thus, the bigger the difference between the mass and maximum load is, the less the scales will be loaded, which increases the durability.

Resolution / readability
The resolution and readability is in most cases dependent on the weighing range. For a weighing range of 1,500 kg, a typical value for a resolution would be 0.5 kg. Usually, the resolution can be calculated on the basis of the weighing range. This is mostly a three-thousandth of the weighing range. However, PCE Instruments can offer an even better resolution for certain hanging scales. Should the usual resolution steps be not enough for you, you are welcome to contact our technicians.

Verification / calibration
What is the difference between hanging scales verification and calibration? In both cases, a setpoint is compared to an actual value. However, if verification can only be carried out by the verification authority only, calibration can be performed also by the 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 is required, for example, for the price calculation on the basis of a weight. Calibration, 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 hanging scales do 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, 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 hanging scales. Via some remote indicators it is also possible to save the weights or transfer them directly 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 the weighing data.

Follow-up costs by hanging scales
In principle, maintenance is required for each measuring system. However, the biggest costs 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. This can then be between 90 and 600 € per calibration. The calibration, for example, could be specified in your ISO quality manual. Adjustments to calibrations or consumables such as batteries or battery packs must also be considered.

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 a question, whether you can still receive hanging scales support or order spare parts 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).

Spring scales belong to the group of mechanical balances that do not require a power supply or electronic components for measurement and display. The measuring principle of the spring balances uses the relationship between force and spring travel. For a certain range of values, the distance covered during stretching or compression is proportional to the applied force. Within this value range, the travel of the spring can be displayed as a mass or weight value on the evenly divided scale of the spring balances. Due to their design, spring balances are very robust against environmental influences. It is easy to operate and in contrast to many other types of scales, the spring scales do not require a special place for installation. It can be easily transported and immediately used at the new place of installation.

Measuring range and resolution of the spring scales
The measuring range and the resolution of the measuring scale can be varied via the material, thickness and geometry of the spiral spring. The measuring range can be designed for a few grams, but also for several kilograms. The resolution of the cylindrical spring balances with measuring scales on the cladding tube is usually one hundredth of the measuring range because of the readability. Spring scales with a weighing range of up to 10 grams then has a scales division of 0.1 grams and spring scales with a maximum load of 50 kilograms has a scales division of 500 grams each. The length of the scales thus has a decisive influence on the readability of the values.

Zero point and tare in the spring scales
The zero point can usually be easily adjusted by means of an adjusting screw if the display mark of the spring balances does not correspond to the zero point of the scale. For weighing in, the spring balances can usually be tared in the range of 15 to 20 percent of the maximum load by means of this adjusting screw. In the technical specifications and in the operating instructions of the spring scales it is indicated whether and how far the tare is possible.

Spring scales with a drag pointer
With a drag pointer, the maximum value of a series of measurements can be stored in the spring balances. The drag pointer is dragged along (dragged along) during the measurement and remains – even when the spring is unloaded – at the point of maximum force application. This maximum value can be left as an orientation value for further measurements or simply moved back to the zero position.

Accuracy of the spring scales – calibration
The measuring accuracy of the spring balances is usually 0.3 percent, and thus is often even better than the resolution. However, in the models of high-quality designs, the accuracies of 0.2 or even 0.1 percent can be achieved. The measuring accuracy can be checked through calibration. Calibration means that the spring scales are loaded with calibration weights and the display results are compared with the mass of the test weights. On request, the spring scales can also be supplied with a manufacturer's certificate of accuracy.

Models and designs of the spring scales
In the most common version with a tube, the elastic spiral spring is located in a cylindrical housing with the measuring scale. At the upper end of the housing there is a suspension bracket or hook on which the spring scales can be held or suspended. At the bottom end there is either a hook or clamp to fix the items to be weighed. The spring is connected to an indicator mark which, when a load is applied, is shifted from zero to the position on the scale corresponding to the current load.

Another version of the spring balances with a circular scale and hands (as in mechanical watches) is called pointer-type quick scales. This design is also used for higher loads. In the simple version of these spring scales, two spiral springs are arranged in parallel. Between them, a rack is mounted on the lower mounting bracket, through which the load is transferred to the springs. When the load is applied, the springs are stretched and the rack moves down. Then because of the rack, a gear wheel and a pointer on it turn. The straight-line movement of the springs is thus converted into a circular movement for the pointer deflection via the rack and the gear wheel.

Tensile and compression force measurement with the spring scales
Spring balances are put under tension for weighing. Since the mass is measured via the weight force caused by gravity, the spring scales can generally also be used to measure the tensile forces. They are then called a force gauge or occasionally a dynamometer and have a scale inscription in Newton. If the spring scales are to be used for tensile measurements where the direction of the force does not coincide with the gravity, it is important to note that in the specification of the spring scales the measurement position is not specified as vertical, but as arbitrary. The measurement position describes the position of the spring axis. The vertical position is always used for weight measurement by attaching the piece to be weighed.

Also compressive forces can be measured with the spring scales equipped for this purpose. There are devices that are already equipped to measure both compression and tension forces. On one side of the spring the tensile force is initiated, on the opposite side – the compressive force. For the other spring scales an easy-to-mount pressure set is available. Also here a rod, which transmits the compressive force to the spring, is used for the pressure measurement. The spring is compressed by the pressure and moves the indicator mark along the scale. When measuring, it is essential to ensure that the compression rod is placed on the measuring surface at right angles. There are various adapters for the tip of the compression rod with which the pressure is transmitted to or from the part to be tested. For the pressure testing of sensitive surfaces, for example, pressure discs with a diameter of 20 mm and padding can be used.

The spring balances are suitable for many different applications due to their insensitivity. They require neither mains connection nor batteries, they can be used outdoors without any problems and can even be sterilized if processed appropriately. The spring scales with a suitable measuring range can also be used as letter scales or to determine the weight of paper, coins or jewelry.

In school and education
Spring scales for tension and pressure measurement can be used to clearly explain many of the mechanical parameters. For example, it can be shown how friction and inclination of a surface influence the amount of force that must be applied to pull a certain part over an inclined plane. Or, it can be demonstrated how the shape and area size of the pressure peak affect the surface under pressure.

In agriculture
The spring scales can be used not only for quick and easy weight control of fruit, vegetables and field crops directly in the field and for animals directly in the barn, cage or pasture. The spring scales can also be used to determine the harvest date of fruit by measuring how much of the tensile force is required to detach the fruit.

In medicine and healing
The spring scales are used, for example, to monitor infusions and for myofunctional therapy in speech therapy. For the infusion scales, the scale is inverted so that the infusion volume already transferred can be read off directly.

In technology
Pressure and tensile forces can be easily and straightforwardly checked with the spring scales during production and also on components already delivered. Examples are the resistance of pushbuttons and the opening or closing forces of already installed revolving or sliding doors.

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

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

They are often recommended in the loading ramp area, where the weight of the load can be read directly. However, they 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 show hanging scales during application. On the left you can take a look at the PCE-CS HD series hanging scales being used in a galvanized installation. As you can see the device is hard to reach in this particular situation, but its infrared remote control allows a comfortable and safe operation from a distance. The picture on the right shows the PCE-CS 3000N series hanging scales during operation. Due to its large illuminated LED display, the measured values can be read even when standing far away. This improves the safety at work when weighing out heavy loads.

Hanging scales need to be verified when they are used to determine the price of a product according to its weight.

Verification certificate for hanging scales be performed by the local authorized specialist, or by associates of PCE Instruments Company. Once an official verification is done, the hanging scales cannot be recalibrated using an external calibration weight. The first verification 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 hanging scales, recalibrate them annually or to obtain an ISO calibration certificate.

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

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

Depending on the model, the hanging scales may be either mechanical or digital (electronic). The former can often be seen at the market, shops, farms, post etc. and they possess a dial or sometimes a vertical numerical scale. This type of scales, in particular, the parts of them, are often made of stainless steel or aluminum which makes them resistant to corrosion, durable and convenient to use. The advantage of the electronic hanging scale is not only an illuminated display, but many other “conveniences” which electronics brings with it, like, easy data transfer, reading and storage of the results, connection with the other devices by means of Bluetooth, very quick and precise weighing, numerous functions facilitating and improving the weighing process (like tare function, over-load indication), rechargeable battery, etc. Some of the models are even controlled by means of the remote control.

The “magnificent” modern load cells which are an important part of the electronic hanging scale provide the possibility to use the scale anywhere (any weather and environmental conditions, vibrations, shocks etc.), and nevertheless obtain precise accurate results. Some of the electronic scales have got a function of self-calibration and are supplied with calibration weights.

PCE Instruments subjects the hanging scales to an independent quality control test. The safety for the user / operator must always be guaranteed. The tests take place in a machine factory or in the test laboratory of a university (depending on the measuring or weighing range of the respective hanging scales). Please have a look at the attached PDF German document .

Here is an example of a test report of the PCE-CS 3000HD:

Test procedure: tensile test

1. Description of the experiment
Mobile hanging scales of the type PCE-CS 3000HD, with a maximum load of 3000 kg should be checked for overload.

2. Results of the tensile test
The hanging scales were tested by means of a tensile test at different load levels. The load levels were 30 kN, 60 kN and 90 kN. The hanging scales were loaded and unloaded 10 times at each load level.

3. Summary
The hanging scales passed through separate load levels without any noticeable damage. As can be seen from the curves, the first load curve of the load level 60 kN indicates a slight plastic deformation. This is more obvious in the first load curve of the load level 90 kN. This is due to the fact that the shackle, fastening eyelet and hook were plastically deformed by the increasing load in accordance with the stress. The irregular sequence of the load curves is due to the fact that the hook could not always be loaded at exactly the same place due to the construction of the hanging scales, and therefore different paths resulted. Below are the load diagrams for different load ranges and the summary of all the load levels in one diagram.