The students who attended Police Day at the Joseph Coviello Recreation Center in West New York on May 16 found out after Sergeant Brian Fava explained the process.
"[The Breathalyzer machine is] trying to shine a light through the fluid," said Sergeant Brian Fava, explaining that when you blow into a Breathalyzer, the machine is actually collecting fluid. "The more alcohol that is in your system, the harder it is for the light to get through."
Police Day is an annual event in West New York in which kids and other residents can learn about police procedures and equipment.
"This event brings the community in," said West New York Police Director Joseph Pelliccio. "It shows [the community] what law enforcement is all about."
"Being a police officer is more than just walking the streets and chasing bad guys," said Pelliccio. "Community involvement is about 90 percent of [police work]."
Although President John F. Kennedy declared the second week in May as Police Week in 1963, West New York has been celebrating with community based events for about 15 years.
"Today is actually National Police Day," said Deputy Chief Thomas O'Donnell at the event on May 16.
Along with the Breathalyzer machine, a traffic light, a speed radar detector, and fatal vision goggles were also on hand for kids to try out.
"You can't even see," said Rick Fresse, a seventh grade student at Public School No. 3 after wearing the fatal vision goggles. "It is all blurry. You can't even walk straight."
Fatal Vision goggles show people the effects of alcohol by allowing them to see as if they were under the influence of alcohol. The goggles can simulate different degrees of alcohol intake.
Outside the recreation center, visitors to the event were able to sit in a police car or on a motorcycle, look inside an EMS truck or climb on the ladder of a fire engine.
Police uniforms and patches were also on display.
"There are so many different branches to the department," said Pelliccio, pointing to the Traffic and Motorcycle division, emergency response division and internal investigation division patches. "You just don't realize that until you see the patches."
The officers also showed off the parts to the uniform that aren't worn everyday. Riot gear, such as bulletproof vests and shields, were brought out for this occasion.
"We would only use this equipment in an emergency situation," said Lieutenant Robert Schwarze. "This is not part of the everyday officer's equipment."
The riot gear also included a straightjacket.
"We would use this if someone wanted to do harm to themselves," said Schwarze.
Along with the West New York Fire Department, North Hudson Regional Fire and Rescue, West New York Emergency Management Squad and the Hudson County Sheriffs department brought their equipment to the event.