Custom Scales Glossary of Terms
How close the displayed value is to the actual value. Different scales have different specified accuracy. Industrial scales are usually based on strain gage load cells. They can typically have accuracy levels of 1/10 of 1 percent. Higher precision scales, such as Surface Acoustic Wave scales, may have ten times better accuracy levels of 1/100 of 1 percent.
To total more than one weighing cycle. Accumulation can be used for both weight, and for parts counting scales, the number of pieces.
The ability to also show letters allows a scale to have a friendlier user interface. Older technology scales are “numeric” and can only display numbers, along with indicator lights.
The temperature of the environment in which a scale is located. When the ambient temperature changes, it may affect the weight reading of the scale. Ultra precision scales, such as Surface Acoustic Wave scales, are affected to a much smaller amount.
A voltage or a current output that is proportional to the weight on the scale platform. Two typical outputs are 0 – 5 vdc, and 4 – 20 ma.
For Parts Counting Scales, this is a feature that allows the scale to automatically determine the weight of the part that is being counted.
Upon actuation, this function automatically subtracts the weight of an empty container on the scale platform and stores this value in memory.
A scale that continuously and automatically maintains a zero indication with no applied load on the scale. It affects weighing amounts around zero, not amounts where a tare value is used. Products with this feature allow 0.5, 1 or 3 divisions of Auto Zero Tracking, or to turn Auto Zero Tracking off. For operations that require adding very small amounts of liquid or powder, Auto Zero Tracking can display the incorrect weight by capturing the weight change — this can be resolved by using a Fill Mode or turning Auto Zero Tracking off (if allowed).
A system of measurement based on the pound (16 ounces or 7,000 grains). One pound is equal to 453.59 grams.
The lighting on the background of a display. This is usually an LED backlight on an LCD display, in order to increase legibility. This setting can typically be changed through menu the options on a scale.
A scale designed to be used on a counter or bench, often for industrial applications. It usually has a higher capacity and lower resolution than a balance.
Adjusting an instrument by comparing it to a known point of reference or standard unit of measure. Calibration is important to maintain the accuracy of a scale, as the accuracy of all weighing instruments can be affected over time by local gravity, aging of the transducer components, and other factors. Most scales are calibrated prior to leaving the factory, but they can be affected by the shipping and travel to their final destination, so scales should be calibrated at the time of installation. Calibration should also be performed periodically to maintain accuracy. Periodic calibration may also be dictated by certification requirements and laws, as well as by the operations’ standard operating procedures. There three types of calibration: Manual (by adjusting a screw), Semi-Automatic (the scale prompts the user to place a known weight on platform), or Automatic (the scale calibrates itself).
The maximum weight that can be measured by the scale on its platform. When combined with a minimum load value (typically 0), this is the scale’s Weighing Range.
A weight instrument that measures the weight of individual objects, and then compares that weight to a pre-determined standard in order to distinguish whether the item falls within the correct weight range. Output signals are often used to actuate external devices.
To determine the total number of objects on the scale platform or in a container. Parts counting scales determine the weight of an individual part, and can then automatically determine the number of parts in a container by the total weight.
The change in load cell output that occurs with time while all other factors remain constant. This is often a function of the material of the load cell and the stress that it experiences. Arlyn’s Surface Acoustic Wave Ultra Precision Scales have much lower levels of material stress, and therefore better creep performance.
The voltage applied to the input terminals of a strain gage load cell. The analog output voltage of this type of load cell is dependent on the excitation. Arlyn’s Ultra Precision scales do not have excitation voltages because they use fully digital transducers.
This scale feature is used to fill containers by weight. This is often used for powders, liquids, and other items that can be fed into a container. The filling mode often provides users with a graphical representation of the filling process and lets the user know how close they are to filling the defined target weight. The results can be sent to a computer and printed.
A platform scale that is designed to be installed at or near floor level. They are available in a variety of materials, including steel, stainless steel and aluminum.
Allows user to easily reproduce a recipe of multiple ingredients over and over again. The balance prompts the user to add each ingredient in the correct pre-determined amounts, and it will track the results upon completion. The results can be sent to a computer and printed.
The lowest unit of readability of the scale. For example, a typical industrial scale with a capacity of 100 lb would have a graduation of 0.02 lb. Arlyn’s Ultra Precision 100 lb bench scales have a graduation of 0.001 lb, which is 20 times better.
The total weight of all items on the scale, including containers and wrappers that contain a set of goods.
A scale that is designed to be hung from a support and the item to be weighed is suspended in the air.
The smallest unit amount that can be recorded by a digital device in a normal operation. See “graduation”.
Scales are typically supported by a leg in each of the four corners. These may be adjusted so that the scale platform is level.
The difference between a scale’s displayed results and a theoretical straight line between 0 and the maximum capacity. The higher the deviation from the line, the less the linear accuracy.
The amount weight or force applied to the platform of a scale.
A transducer which translates the downward force on a scale into a proportional electrical signal, which is then converted by the hardware and software to display a corresponding weight on the display. Most load cells produce an electrical signal which is analog. Arlyn’s Ultra Precision scales produce a digital signal.
Mass is a fundamental characteristic of a body — a numerical measure of its inertia; the quantity of material in a body. It is constant regardless of gravity, and it is distinct from an objects size or weight. Electronic scales measure gravities’ force on an object, which is converted by the scale electronics into a mass value based on a calibration factor.
The metric system is an international measurement system based on the decimal system. For weight measurement, it is based on the kilogram, so it is also associated with the gram and milligram.
The weight of an item minus the weight of a container that it is being weighed in. For example, when filling a tank, this would be the weight of the contents of the tank, not including the weight of the tank itself.
A difference in the weight of an object measure in the center of the platform compared to the weight at half-distance from the center to the end to the platform.
The load amount where the gross weight on the scale exceeds its capabilities. The scale will be damaged if the amount of weight exceeds the safe overload capacity. For strain gage industrial scales, a typical allowance for overload is 150 percent of the rated capacity of the scale. Arlyn’s Ultra Precision Scales have higher overload capability.
This is another name for a scale platform. It is the part of the scale where the load is placed.
Counting how many individual parts are in a group by recording the net weight and dividing it by the average weight of a single piece (Average Piece Weight). The Average Piece Weight is determined by a small representative sample of the product being weighed, such as ten pieces or fifty pieces. The accuracy of counting parts involves the accuracy of the scale, the accuracy of the Average Piece Weight and the consistency of the parts being counted. Scales may require additional software or counting items into a container. The overall resolution of the scale is critical for accurate parts counting. Arlyn’s Ultra Precision SAW scales provide resolution that is ten to twenty times higher than standard industrial strain gage counting scales, making them ideal for parts counting .
The flat, horizontal top section of a scale that is designed to be the load receiving element. Important features of a platform include its physical size, and the material from which it is constructed.
A type of industrial scale that is usually used to weigh moderately large and heavy loads. Typically, a platform scale may have a capacity ranging from 500 lb up to 5000 lb. Platform sizes may range from 2’ x 2’ up to 5’ x 7’, and even larger.
The amount of electrical energy that is required to run a scale. Modern industrial scales use only moderate amounts of power, and in many cases may be run by a battery.
Scales that have higher precision than the typical industrial scale. Most strain gage industrial scales have accuracy levels of about 1/10 of 1 percent. This is suitable for many industrial applications. But when higher accuracy is needed, Arlyn Scales high Precision Scales offer accuracy that is ten times better.
A function that uses a tare weight that is entered by the user or recalled from previous memory. Multiple pre-set tare memory in the scale allows the user store multiple container weights for easy access.
The information a scale outputs to a printer. A variety of printer types are available, including label printers and bar code printers.
The smallest fraction of a division that a scale can show on its display. The smallest difference in mass that can be displayed (commonly labeled as ‘d’). This may also be called divisions or increments. It must be specified with a tolerance for repeatability and linearity for the most accurate product comparison.
The differences seen on a scale measuring the same amount over time, expressed as a Standard Deviation (1 σ). The less accurate the scale is, the higher the amount variability will be.
The total number of divisions that a scale can display, calculated from the capacity divided by readability. Expressed as a ratio 1:x,xxx, or in divisions x,xxxd or x,xxxe.
An programmable target weight that, when reached, will activate an electrical output. Set Points may be used for automatic filling, for tank monitoring, and other automatic processes.
A calibration process which is performed on a scale so that the displayed weight is the same as a test weight placed on the scale platform.
The degree of consistency of a measurement instrument when subject to variation in external factors, such as temperature, time and voltage.
A metallic foil on a plastic backing l that is bonded to a surface and elongates or contracts with that surface. The resulting deformation causes a change in the gage’s electrical resistance and permits the measurement of the deformation.
An acoustic wave traveling along the surface of a material that exhibits elasticity. Most scales use strain gage cells that are based on a spring element, usually made of aluminum or steel, that is very fragile and more susceptible to changes in temperature. Other high accuracy scales are force restoration scales, in which their platform is directed by a very precise (but expensive and fragile) flexure system. Ultra precision scales that use SAW technology will measure displacement instead of the strain on the spring element. This results in the scale load cell operating at 10 percent of the strain levels found in strain gage scales, with none of the errors associated with springs and 5 times the ruggedness. SAW scales provide accuracies of about 1/100 of 1 percent, which is ten times better than strain gage scales, and equivalent to force restoration scales.
The value of the weight of a container or other item that has been placed on the scale platform, that is not part of the object being weighed. The tare weight subtracted from the gross weight is the net weight of an object.
The range within which a scale can still display a net weight after taring a container.
A weight solely created for testing and calibrating scales.
A mechanism for converting energy from one form to another for information or control purposes. The transducer in a scale is the load cell, which converts the weight of an item into an electrical signal.
The time required for a scale to reach thermal equilibrium once powered. Usually 30 minutes or less if the scale has acclimated to the environment.
The unit that is associated with a weight or mass. Common weighing units are Avoirdupois (measured in pounds, ounces, tons, Graines, pennyweights, troy ounces and carats) and Metric (kilograms, grams, milligrams, metric tons). Some units allow custom unit of measurement to be defined by the user.
The downward force of an object that is being acted upon by gravity. A weight may also refer to a metal object with a defined mass that is used for testing purposes.
A break-through scale technology patented by Arlyn Scales that allows for ultra sensitivity (.001lb), ultra capacity (between .01 percent and .005 percent), ultra stability (a change of less than 3 parts per million per 1° C), and ultra rugged (2.5 times the weighted load of average scales). They use Surface Acoustic Wave technology to provide 10 times the accurate of other scales within the same price range.
An adjustment of the gross weight displayed on a scale to zero, with the zeroing range limited by software and new zero value affected by Auto-Zero.