High Precision Scales used for Aggregate Testing

large-ultra-precision-scale-1A number of related fields require understanding the particle composition of aggregate materials. These include asphalt production, the manufacturing of concrete, cement, and cement products, soil testing, construction testing, and particle sizing, among others.

Asphalt is commonly known as the common black material that is used to pave roads. It is also known as tarmac, blacktop, or macadam. But it actually has a number of different components.

Generally, the largest single ingredient is crushed stone. Depending on the expected use of the asphalt, the standard size of the individual stone pieces is specified. A number of other complementary materials are also used, such as gravel and sand. 

These components can make up as much as 90 or 95 percent of the total asphalt material. But it obtains its material properties and color from the black liquid binder material that holds it together, the asphalt cement. It is a very sticky black liquid that is a petroleum by-product. 

Similarly, concrete is a mixture of a number of individual ingredients where once again, the primary ingredient is crushed stone and gravel. By itself, these make up more than 40% of concrete material and sand composes another 25% of the total. Water and Portland Cement include most of the remainder of the non-cured material.

What Is A Gradation Test For Aggregate Industries?

As with asphalt, the properties of cement are highly dependent on the particle properties of the materials used. Of course, materials such as gravel, crushed stone, and sand are far from being uniform. Any sample will consist of individual pieces of varying sizes. 

In order to determine the percentage of each range of sizes, it is necessary to take a sample of the material and then separate out each various size. The procedure used to do this is known as sieve analysis or gradation test. This can be thought of as using a number of different screens or strainers. 

Each strainer has a wire mesh screen with different screen openings. First, the material is poured into a screen with the largest openings. Only the largest particles will be captured at this first stage and the remainder of the particles will pass through.

 This remainder is then poured through the second-largest screen and as previously, only the second largest set of particles will be captured. This process is repeated with the desired number of different-sized screens, resulting in a collection of particles that match the screens used. Of course, to operate efficiently, the strainers may be stacked, and the stack may be mechanically shaken so that all the different sizes are collected at the same time.

Using Industrial High Precision Scales For Aggregate Testing 

The stack of strainers can be disassembled for access to each size. Now each of the particle collections may be weighed. The percentage of the total composed of each particle size can be calculated, and then compared to the required material specifications. 

The weighing systems used for this purpose must meet some very difficult requirements. They must have a very significant capacity because samples of aggregate materials may easily weigh 100 pounds and they must be very rugged, as large amounts of aggregate materials will be dumped onto the platform. Most importantly, they must be very precise so that the percentages calculated will be exactly accurate.

Standard load cell-based industrial scales will generally not be accurate enough. The most common solution is to use a type of digital scale known as a force motor balance. For these high capacities, these scales will be extremely expensive and they are also not particularly rugged.

Key Features Needed For Aggregate Testing

A new scale system technology, introduced by Arlyn Scales, uses Surface Acoustic Wave, or SAW transducers. These Ultra Precision Scales combine all of the required features of high capacity, extreme ruggedness, and exquisite accuracy. For example, the 100-pound capacity industrial scale has a readability of one-thousandth of a pound, an accuracy of greater than one-hundredth of one percent, and an overload capacity of more than two and a half times the rated load.

As an added advantage, they may be equipped with an optional battery pack, making them ideal for use at construction or paving sites. It is often necessary to record the particle size percentages.

These Ultra Precision Scales may be equipped with a USB connection that accepts a standard USB flash memory drive. Thousands of readings may be stored on the drive. This data can then be downloaded into any computer system.

When used with a database program, or entered into a spreadsheet, the data can easily be compared with the required aggregate specification. Alternatively, the digital scale can be directly connected to a computer system using a serial RS-232 communication connection, or with a wired or wireless Ethernet port. Arlyn’s cloud-based application, AExchange, can remotely collect this data from the field.

The Arlyn Scales Difference

Aggregate testing requires scales and weighing equipment. But because it is such a demanding application, you need to be equally demanding of the scales that you use. Another parameter that is in very high demand is a reasonable cost.

Traditional scales can meet the cost requirement, but not the accuracy, and force motor balances meet the accuracy requirement, but not the cost. Only Arlyn’s ultra-precision SAW scale provides the accuracy needed and an acceptable cost. When you have demands for aggregate weighing, demand Arlyn Scales.