Triple beam balance, a traditional mechanical balance, is often used in physics or chemistry classes.

Although both triple beam balances and analytical balances are used to measure the weight of certain objects, there are differences in multiple dimensions.

Structures

A triple beam balance comprises a base, a platform, an adjustment knob, three beams with three sliding weights and a magnetic damping system.

An analytical balance is consisted of a weighing pan, an anti-draft ring, a display panel, a keyboard, two glass doors, four leveling feet, a level bubble, a rs-232 interface, a power inlet, a power cable, a calibration weight, a battery and the balance main body.

Principles

A triple beam balance works on the Principle of Moments, the sample on the left weighing platform and the weights of known mass on the right beams are kept in balance, thereby the mass of the sample measured.

An analytical balance is equipped with an electromagnetic force sensor. So the working principle of an analytical balance mainly lies in the fundamental of an electromagnetic force sensor. When gravity is applied to the weighing pan, the lever under the weighing pan drives the coil connected to it to move in the magnetic field, and the coil is energized to cut the magnetic field, thereby generating electromagnetic force, then the current signal will be collected, processed by MCU and converted into a weight which displays on the panel.

Accuracies

Triple beam balances are usually able to measure 0.01g, 0.1g, while analytical balances are capable of determining the weight from 0.1mg to 0.0001mg. The difference of accuracy determines the difference of applications.

Uses

To use a triple beam balance, first slide all three sliding weights to the left, adjust the knob under the platform until the pointer returns to zero, and then place the sample to be measured on the platform. Then move the three sliding weights in the order of mass from high to low to balance the left platform and right beams. Once balanced, read the readings of the three sliding weights in the order of mass from high to low to calculate the mass of the sample.

Note that the mass of the sliding weight on the middle beam is the largest, the sliding weight on the rear beam is the second largest, and the sliding weight on the front beam is the smallest.

For analytical balances, first tare the balance under no-load state, then open the side door, put the sample on the weighing pan and close the side door, the weight will be measured and displayed on the screen.

Clearly, the operation of a triple beam balance is more cumbersome, while the operation of an analytical balance is simpler.

Prices

It is not difficult to conceive that analytical balance will be more expensive than triple beam balance. The price of a triple beam balances ranges from $20 to $800 according to its capacity and accuracy, while that of an analytical balances ranges from $300 to $50,000 depending on its accuracy.

The price of a 0.1g triple beam price is usually from $30 to $200, while the price of a 0.1mg analytical balance is usually between $350 and $600.

All the foregoing discrepancies determine the difference in applications of these two kind of balances, so just select the one that is capable of perfectly helping your work.

References:
[1] sciencestruck.com. : Triple Beam Balance: Function, Parts, and Uses. https://sciencestruck.com/triple-beam-balance-function-parts-uses
[2] Mr. Beiter's Awesome Youtube Channel. (2013 August 29): Tutorial: Triple Beam Balance.
https://www.youtube.com/watch?v=BAf6HoVK6JI
[3] us.ohaus.com. : Triple Beam Balance 700 Series. https://us.ohaus.com/en-US/Tutorials/Triple-Beam
[4] flinnsci.com. : Flinn Triple Beam Balance Operating Instructions. https://www.flinnsci.com/api/library/Download/db841c44c5bc4d3abfb23ff5c6e73371
Dennis Hartman. (2018 March 13): Electronic Scale Vs. Beam Scale. https://sciencing.com/types-scientific-scales-6892005.html