Truck scales are used everywhere where goods are transported and recorded, in industry and agriculture, in warehouses, customs and large transport hubs. The most popular today are automobile electronic scales, the measurement accuracy of which is much higher than that of their mechanical counterparts. Scales can be equipped with weight display devices of varying degrees of complexity: from simple electronic indicators to complex transmitting devices included in a single network.
Car weights
What is a truck scale? These are devices that allow you to weigh the goods transported by road without unloading it. In addition, the load on the roadway is monitored using truck scales.
By design, there are automobile platform, mortise and ramp scales. Ramps, however, are also equipped with platforms of different sizes. Such truck scales (80 tons, 100 tons or 120 tons, for example) are suitable for weighing even the heaviest loaded vehicles.
Mortise scales are equipped with a metal platform mounted at ground level. It is convenient to call on such scales, maneuver on the weighing platform and leave it.
Platform truck scales can be equipped with a platform of reinforced concrete, consisting of several modules.
Ways to install truck scales
The installation method distinguishes between:
1. Stationary truck scales are installed on a concrete foundation with a sand and gravel cushion. The choice of foundation is determined by the maximum load capacity and length of the scale. Check-in is possible on a concrete or metal ramp.
2. Baseless automobile scales - mobile devices that are stacked on road slabs. This method of laying is possible for all types of scales, restrictions exist only for some climatic zones and certain types of soils.
3. Automobile deadweight scales are mounted on the foundation foundation at the same level with the road surface. With this installation method, ramps and side rails are not needed, but there must be a drainage system.
4. Portable underfloor scales of simple design and small dimensions are laid directly on the road surface or dense ground.
Baseless scales
Truck scales, for which a stationary foundation is not needed, are considered the most popular today. They are installed, as a rule, in places of seasonal or temporary work with a small flow of goods.
Scales consisting of several modules that are easy to transport, load using a truck crane and mount without welding are generally called foundationless or sometimes gauge.
The modules are mounted on a special metal frame. The frame is installed, as a rule, on reinforced concrete slabs, under which a pillow of crushed stone or gypsum-sand mixture (GPS) is prepared in the most thorough manner.
Ramps are provided for entry and descent of the car.
The load on the truck scales (60 tons and 80 tons the most common) may depend on the design of the device from 20 to 100 tons.
Ramps of foundationless scales
In auto scales ramps of two types are used. As a rule, four metal devices that are attached to the end modules under the track of the car are included in the package.
A cheaper option is a bulk ramp. An embankment of crushed stone and GPS is built to the end module for the car to enter, onto which road slabs, concrete or asphalt are laid. Depending on the conditions and lifetime of such a device, it may turn out to be cheaper and more convenient than a metal structure.
Benefits of foundationless scales
Today, foundationless scales are in demand on the market. And that is understandable. Firstly, installation time is saved, because there is no need to fill the foundation and wait for weeks until it hardens. Baseless products can be installed in one to two days.
Secondly, truck-mounted scales are foundationless, the price of which is significantly lower than the counterparts installed on the foundation, require lower installation costs, as there are no costs for materials and labor for pouring the concrete base.
Thirdly, they are mobile. They are easy to assemble and disassemble, if necessary, transport from place to place, without using expensive special equipment.
And there is another advantage that distinguishes the foundationless scales. Automotive measuring devices can be increased to weigh long trucks or road trains by connecting additional modules to the load platform. The length of the platform can be either 6 m or 24 m.
The longest prefabricated design is designed for one-time weighing of the road train. For such purposes, truck scales are used, 100 tons for which is not an upper limit.
Disadvantages of foundationless scales
The main disadvantage of this design is the regular monitoring of the installation, for which it is necessary to use a level.
After all, not rigidly installed plates can skew. And this entails not only a low measurement accuracy, but also a complete failure of the load cells.
As a rule, the design of the support frame provides for special nodes for adjusting the sensors so that the specified elevation heights of the load receiving platform are kept unchanged in case of a slight change in the position of the plates (subsidence or skew). And after each setting, an extraordinary calibration of truck scales should be carried out. And since this procedure must be carried out by the state bodies of the metrological service in accordance with state standards, this entails additional costs.
Main characteristics
Choosing a truck scale, first of all, pay attention to the largest weighing limit. Briefly, it is referred to as "LEL" and means the maximum mass that a particular balance can measure. It is best to choose a balance with a load capacity of 10-20 tons. For example, if the mass of cars with cargo is mainly 65-70 tons, then the carrying capacity that automobile scales must have is 80 tons.
The second important indicator is considered the smallest weight limit. Not everyone pays attention to him, and in vain. In any case, it should be less than the mass of the lightest empty car to be weighed.
The third important indicator is the measurement error, which depends on the LEL, and the cost of calibration.
Calibration allows you to determine the actual values of the metrological characteristics of the car. The balance can be with an external or built-in calibration weight, with automatic calibration.
Components and dimensions of truck scales
When choosing weights, it is necessary to take into account the weighing mode (in static or motion) and design features.
Platform automobile scales for static weighing have platforms of rather large sizes, while dynamic weighing is performed, as a rule, on two underlay weighing modules.
To determine the mass of trucks of different sizes, naturally, different sizes of the platform are needed. For example, ZIL, KamAZ or GAZ with a body can be weighed on scales of 6 m long, heavy-duty MAZs - 8-12 m long, trucks and cars with a trailer - 18 m. For road trains, the carrying capacity that automobile scales must have is 100 tons, length - 24 m.
The load receiving platform may be reinforced concrete or metal. The first option is intended for quarries and factories of reinforced concrete products, the second is universal.
Either electromagnetic, or strain gauge sensors, or Tuning-Fork instruments , are used as weight-transmitting devices. It is very important to pay attention to the protection of sensors from both moisture and dust, and from vandals. Modern truck scales of all manufacturers are equipped with a function that eliminates the tare weight, and is also equipped with an interface that allows you to connect to a computer network.
Safety during operation of the balance is ensured by standard or reinforced lateral limiters, which protect against accidental exit from the platform.
Supplier Selection
Having decided on the parameters and technical characteristics, you need to seriously approach the choice of supplier. Firstly, different manufacturers, with the external similarity of the design of the scales, offer different equipment. Best of all, if the package comes with software, electronic components, including cables.
The accompanying documentation should indicate the degree of protection and temperature conditions for the operation of the equipment.
It is advisable that the supplier not only supply the measuring equipment, but also install it, and subsequently during the entire service life carry out the necessary service and repair.
Features of mounting foundationless scales
In the accompanying documentation for truck scales, the necessary recommendations for installing road plates as a base under the frame are indicated. You can install foundationless truck scales on slabs that are laid on a gravel road or dirt road, and on specially prepared dumping.
Options and prices
The basic scope of supply for the scale usually includes:
- load receiving device, which is a set of modules of the load receiving platform of the scales;
- frame for baseless installation;
- driving metal ramps;
- limiters from longitudinal and lateral displacements;
- load cells loaded with supports;
- weight converter;
- connecting, signal, cables for connecting to a computer;
- blocks matching the characteristics of load cells;
- mounting units and parts;
- software;
- passport for scales, operation manual, user manual, warranty card;
- typical construction task.
The truck-mounted scales differ without foundation (the price for them, of course, also varies) in design, size and configuration.
For example, a foundationless scale with a platform, the length of which is 5.9 m, a load capacity of 30 tons, sensors that are as dust-proof as possible, with an average class of measurement accuracy cost from 400 thousand, automobile scales with a 60-ton load capacity with a platform length of 12 m are more than 680 thousand and designed for 100 tons with a platform length of 24 m - 1.2 million rubles.
For cargo accounting, weighing is a priority. Today, manufacturers offer many options for truck scales to perform a wide range of tasks in various fields of industry and agriculture, in different price categories.