Lie detector tests have captured people’s imaginations for many years. Since their initial invention in Berkley, California in 1921, polygraph machines have been controversial, fascinating, and widely used for many different purposes. There are two main uses for a polygraph test, with the price of a polygraph varying based on what you want.


How Do Polygraphs Work?

Lie detector tests can’t automatically determine if a statement is truthful. Instead, they are a complex machine that monitors several aspects of the body that indicate stress levels like blood pressure, perspiration, and heart rate. The examiner asks several control questions while monitoring these physiological aspects, and then asks several questions which someone wants to know the validity of. By comparing the body’s different responses, a polygrapher can determine if it’s reasonable that the person is telling the truth, or a lie.


The Cost Of Personal Polygraphs

Reality television and various talk shows have popularized the notion of using a lie detector test to catch a cheating spouse in the act, but this is not far from a realistic use of the polygraph machine. Many centers in major cities will offer polygraph examinations with a licensed and professionally trained polygrapher. Depending on the intensity of the examination, these sessions could cost anywhere form £200, a cheap lie detector test when compared to the cost of more intensive exams used by corporations and government agencies.

For those how decide to pay for a lie detector test for personal reasons, some dating and relationship experts have come out in favor of the polygraph as a tool to help rebuild trust. The idea is that a couple that have experienced trust issues in the past, such as an affair, can come to a licensed polygraph center and go through an examination. Giving their partner more peace of mind that they are being honest. The counselors who have come out in favor of this stress that a polygraph should not be used to bring out new information, but rather should be a way to confirm existing stories.


The Cost Of Pre-Employment Screening

Another time that you may find yourself using a lie detector test is for vetting new employees or applying for new jobs yourself. Many government agencies use polygraphs to confirm information on a job application and see how their recruits perform under pressure.

These government organizations will often have polygraphers that are employed by the state and not available for public use, but private business owners that want to use a lie detector on potential employees can seek out private polygraphers in there area. The law regarding this use of the polygraph can be tricky though, and any employer wishing to use a polygraph on future employees needs to be sure that understand when it is legal.

The cost of a lie detector for pre-employment screening will depend on the number of people you wish to examine and the intensity of the exams. Some all-day sessions, like those used by the CIA can cost up to £2,000, but there are cheap polygraph examinations available to confirm more basic information.