The 10 Best Postal Scales
This wiki has been updated 23 times since it was first published in August of 2015. Whether you work in a shipping company, a warehouse, or a business that requires mailing packages on a regular basis, you can ensure accurate postage rate calculations using one of these handy postal scales. Many of our options are capable of running on batteries, USB cables, and/or AC power, with the capacity for weighing anything from letters to 400-pound boxes. When users buy our independently chosen editorial picks, we may earn commissions to help fund the Wiki. Skip to the best postal scale on Amazon.
Bearing The Load
When the foil is strained, the circuit board also stretches.
The combination of deformation and stretching allows the strain gauge to convert the force of weight into an electrical signal.
Whether you own a large business with a storefront or you sell products over the internet, chances are you're doing a lot of shipping. This requires many trips to your local post office, which is fraught with disturbingly long lines and overpriced shipping rates. The good news is that you can save yourself both time and money by calculating your shipping costs from the comfort of your own home or place of business using a postal scale instead. This can be done before you even think of stepping foot into the post office.
A postal scale is a device that uses an electronic integrated circuit pressure sensor to calculate the exact weight of a package. The weight value is typically displayed on an LCD located on the front of the scale itself. Unlike a conventional bathroom scale that uses a dial, internal spring, and a series of levers to indicate the weight of an object, the postal scale operates a bit differently. Its components consist of an overall structure, which is the part of the device that actually bears the load; a weight indicator, usually represented by the LCD; a load cell, which converts the force of an object into an electrical signal; and a signal conditioner, the electronic component that powers the load cell. The signal conditioner is also responsible for converting the electrical signal into numbers for the scale to display. But how does this work in a step-by-step fashion?
When a package is first placed on the scale, its force of weight is evenly-distributed by a series of underlying pegs underneath the flat surface of the scale's outer structure. Next, the device's internal components apply the force of weight to one end of the unit's load cell, bending that end downward. This action ultimately deforms the scale's strain gauge, which consists of either metal tracks or foil bonded to a printed circuit board. When the foil is strained, the circuit board also stretches. The combination of deformation and stretching allows the strain gauge to convert the force of weight into an electrical signal. What makes this possible? The internal load cell carries a charge, which means its electrical resistance changes when it bends downward. Once the electrical signal has been generated inside the scale, it passes through an analog-to-digital converter and a microchip. The microchip is responsible for interpreting and translating the signal data into a readable format that appears on the scale's LCD.
The load cell helps determine a postal scale's recommended weight capacity. The greater the number of load cells with which a scale is equipped, the greater the scale's weight capacity. It's important to note that while the scale may accommodate a weight greater than what its load cell can bear, its overall level of accuracy is compromised when used beyond its recommended range. That said, to ensure that proper shipping rates are calculated, it is recommended not to exceed a postal scale's load cell rating.
Keeping It Real And Accurate
Ensuring that your device will prevent you from overspending at the post office is an important consideration. There are plenty of useful features common to postal scales that help make that easier and for which you should be on the lookout when considering such an investment. These include a tare function, allowing for zero calibration without adding additional weight; a holding feature, which maintains a previous calculation on the LCD after removing a package from the scale's surface; and the ability for the device to run on both AC and battery power. The hold function is particularly useful when you're stuck weighing large packages that obstruct your view of the scale's LCD. Having several power options makes the scale easy to transport, which comes in handy if part of your business requires a lot of travel when shipping objects.
A scale with an automatic shutoff feature will save additional power and prevent it from wearing down its internal battery when you're on the go. Some postal scales also include built-in audible alerts when an object's weight stabilizes, so you can be sure that you're getting the most accurate reading possible. Look for a scale capable of displaying weights using different metrics, such as grams or kilograms.
It's also important to realize that shipping rates aren't set in stone. Spending a bit more on a scale that can connect to a computer and Wi-Fi will allow it to have access to the latest shipping costs and updates.
A Brief History Of The Postal Scale
Scales have a long history dating as far back as 2000 BCE to an ancient relic found within the Indus River Valley not far from present day Pakistan. It is believed that this early device consisted of a balancing structure that used two plates attached to an overhead beam and central pole. Weight measurements would be taken by placing objects on one plate with rocks on the other until equilibrium was obtained. Balances also had a significant impact on other civilizations, including ancient Egypt.
Spring scales were easier to use because their readings could be taken almost immediately without any required balancing.
Further technological advances leading to the development of the weighing scale appeared by the late 18th century and are largely credited to spring and scale maker Richard Salter. Following R. W. Winfield's 1840 development of the candlestick scale for letters and packages, spring-operated scales became common throughout the United Kingdom. Spring scales were easier to use because their readings could be taken almost immediately without any required balancing.
The use of various electronic attachments for spring scales was introduced as early as the 1940s for improving weight reading accuracy. Load cells also served to improve scale accuracy through the late 20th century when the use of digital scales became more widespread. Today, postal scales are equipped with plenty of high-tech functions, including Wi-Fi access, built-in calibration software, and lightweight designs with various power options to increase portability for the traveling business.
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