Understanding the technology behind portable truck scales is helpful when deciding which types of portable scales will be the most beneficial for certain tasks at hand. The load cell, or transducer, built into most portable truck scales utilizes force as a measurement tool and then converts the information into an electrical signal which can be easily interpreted and understood.
The four most common types of load cells found in most industrial truck scales include: strain gauge load cells, piezoelectric load cells, hydraulic load cells, and pneumatic load cells. Each type of load cell uses a different mechanism by which they can measure force. Additionally, certain load cells utilize specific attributes that make them more or less efficient in specific circumstances and conditions.
With strain gauge load cells, the most widely used of the four due to their accuracy, life cycles, and resonance quality, strain is measured as the load is applied. The strain gauges, which can range in number from one to four, convert the amount of deformation created by the weight of the load into an electrical signal that is then amplified by an instrumentation amplifier.
The gauges are connected to a beam or bridge that contorts as weight is applied which in turn creates electrical resistance which the gauges can effectively measure and use to calculate weight. These load cells, which are common on many types of portable truck scales provide impressively accurate measurements and are more and more common amongst portable truck scale users.
In the case of piezoelectric load cells, which also utilize deformation as a means by which to calculate weight, their use of piezoelectric material in direct correlation to the strain incurred by the load cell to create voltage output as opposed to the gauging systems in strain gauge load cells can make them a more reliable choice for frequent and strenuous loading conditions.
The standard organization of pistons and cylinders comprise the inner workings of the hydraulic load cell. There are no electrical components to this load cell as it utilizes pressure to measure weight and due to this fact it can be very useful in hazardous circumstances and outdoor environments where other load cells may fail.
Inside of a thin elastic diaphragm, assisted by mechanical stops to prevent excessively heavy loads from over straining it, is where the piston is placed meaning that it never actually comes into contact with the load cell itself. The load cell is filled completely with oil and the pressure created by the load placement onto the piston, effectively moves the piston and diaphragm as the oil pressure changes.
This change in pressure is manifested on a Bourdon tube, which measures gauge pressure instead of absolute pressure which means that vacuum is sensed as a reverse motion. The most common uses of hydraulic load cells are in tank, bin and hopper weighing.
Pneumatic load cells also utilize pressure as a means by which to calculate weight. The way the load cell is designed allows it to immediately regulate the balancing pressure. Air pressure escapes from a nozzle placed at the bottom of a load cell while the other end is where the pressure is administered.
This transfer of air pressure is then measured by a pressure gauge. Pneumatic load cells are not as widely used for truck scale load cells as some of the other models and can have varying accuracy. Understanding the inner workings of load cell sensors is important and can be a great asset when deciding which option will work best for your needs.
So whether you're in search for a portable truck scale for rent or are looking to buy a portable truck scales, understanding what types of load cells in the scale unit can help you invest in the ideal system to meet your needs.