Article

Dirty talk about bill acceptors

In a perfect world, no money is too dirty for a bill acceptor. In this column, John Petkus, president and CEO of currency machine specialist Hemisphere West, tells bill acceptor users to clean up their act.

March 25, 2002

With the increasing integration of bill acceptors into kiosks and ATMs, many end-users

are on a quest to find the perfect bank note validator for their products.

More times than not, the first reference to the operation of a bill acceptor comes from the manufacturer's specification sheet. General operational features are typically the same from one acceptor to another. These include operating voltage, interface specifications, cashbox capacity and overall physical size.

For example, if you require a vertical stacking bill acceptor with a 400 bank note cassette capacity, RS232 (bi-directional) interface and have a 12-volt DC power source, it is easy to find several models.

Each manufacturer will tell you why its acceptor is the best. This is when you will hear the two most common descriptions of how manufacturers try to quantify their units, jam rate and acceptance rate, two very important specifications, but also the two most misunderstood terms.

Accept these bills

Acceptance rate is the rate at which a good bank note will be validated without the bill being returned. This one specification is probably the most subjective, and in some instances, misused term in the bill acceptor glossary.

Typically, the specification reads, "98 percent acceptance rate of good bills." Any bill acceptor manufacturer can and will claim such a high rate.

Picture a lab technician sitting at a table with 100 street grade bills (notes with slight to moderate wear). In this perfect lab setting, I will be willing to bet that any bill acceptor will validate these notes the first time, 98 percent of the time. Since there is no accepted test method or organization to certify bill testing, it is left to the manufacturer. Of course, in a perfect lab setting, you will see such amazing results.

In the real world

To be fair, bill acceptor manufacturers have to give the end user some number to compare with other acceptors. The problem is that in a perfect world; most any bill acceptor will validate high percentages of bank notes. We do not, however, live in a lab's perfect, sterile world.

The moment a kiosk is set in the field, the bill acceptor is subject to many forces that affect how well it accepts bank notes. Several years ago during the Super Bowl, a soft drink company aired a commercial showing a man trying all night to get his bill validated on a soda machine bill acceptor. In the real world, the likely problem would be that the acceptor had accumulated dust and dirt over its internal sensors, or that some foreign object was covering these sensors.

The internal sensors of any bill acceptor are its eyes, so to speak, and if the eyes are covered, their ability to collect data off the bank note will be hindered. I have had potential customers call me and complain that "brand X" bill acceptor company claimed a 98 percent acceptance rate, but after six months in the field the rate was closer to 75 percent or less.

Two key questions

My first two questions are, "How often do you maintain your acceptor," and, "What kind of environment is your kiosk located in?" Often, the answer to the first question is, "We have never maintained or cleaned our acceptor."

Dust and debris on the sensors will dramatically lower acceptance rates no matter what brand of acceptor is being used. Each manufacturer has a recommended maintenance routine, but I have found that a good shot or two from a can of compressed air through the note path does a good job of keeping the acceptor doing what it was meant to do, efficiently taking money.

The answer to what environment the kiosk is located in also goes a long way to letting me know what's going on with the acceptor. For instance, bills used at a kiosk in a water park will often be wet and wrinkled, lowering bill acceptor performance.

Some bill acceptor companies have done a very good job at protecting the internal sensors and optics and also have their currency recognition software tweaked to take into account wet or wrinkled notes. But over time, wet currency will reduce acceptance rates unless you maintain the acceptor. Environment can be the key to why you have chronically low acceptance rates.

Jam session

The Jam rate of a bill acceptor is rarely seen on a manufacturer's list of specifications. As with acceptance rate, this figure is highly subjective. At Hemisphere West a customer once told us of a company claiming its bill acceptor jammed only once in 50,000 tries. In a perfect lab setting rates like this can be achieved, but in the real world no self-respecting company could make these claims, or would. Bill condition, vandalism and other factors will affect the jam rate.

As it turns out, the company did claim a 1 in 50,000 jam rate, but admitted the figure was obtained from a lab test and could not be expected in the real world.

Manufacturers use proprietary methods to reduce bill jams. Several companies avoid magnetic sensors. When magnetic sensors are used, bank notes generally have to contact these sensors. If the bill somehow sticks too long over this sensor, some feel this condition can cause long term jamming problems.

One company uses a unique roller method to pull bank notes over the magnetic sensors without contacting them. Others use magnetic sensors and claim no increased jamming. In short, bill acceptors will jam from time to time, some less than others, depending on external circumstances and to a lesser degree on design.

Clean up your act

The single most important item that any end user should conclude from the above is that a good long-term preventive maintenance routine should be required as part of the overall maintenance of your kiosk. This single action can save you many frustrating hours clearing jams and explaining to customers why the bill acceptor isn't taking money. Bill acceptors these days are well-designed; make sure you make the most of your unit by keeping it clean.