
Have you ever wondered if you can fool any money vending machine?
Almost all of the vending machines in the world including ATMs do not need a human to check if the bills are original. Some vending machines are designed that they can even dispense back the change after a payment.

Vending machines are distributed in several areas such as malls, parking lots and clubs. Apart from dispensing change for payment and receipts, some machines are even programmed to vend clothes, newspapers and electronic goods.

In Kenya, the most common vending machines dispense milk, cooking oil and ice cream.
Many people have always thought that it is easy to fool the machines and deposit fake bills. Some have also thought that inserting the wrong currency in obviously a lesser value can also fool the machine.
How does a vending machine know the difference between a Sh 500 and 1000 note?.
Different from human’s ability to scrutinize money, vending machines including ATMs recognize a bill note using a number of observation mechanisms.

Once a notes gets into a vending machine, it is first scanned through optical lens. There are small photocells that scan the inserted bill an identify a note based on its grain patterns an arrangements.
Even if a note has the right texture, pattern but still fake, there several security features in a genuine note that the machine verifies carefully.

Machines also use sophisticated fluorescent light detectors to scan for special glows in notes that only visible through lights of certain wavelengths.
The ink used to print currency is magnetic and machines use magnetic readers to know the value of the currency.
For coins their value is determined using physical properties such as weight and size. Weight and size of the coins is put in place by having different diameter sizes and the thickness of a coin.

However, even with all those measures, you might have heard of an ATM dispensing fake notes. In such a case, it is likely that the machine was tampered with.
Thus said, you now know why your note or coin maybe rejected by a vending machine.