Polygraph is a machine that is used in detection of lies. It is used in several situations either in investigations or even while applying for a job.
The machine has several sensors that are fixed on the persons who is about to take the test.
The polygraph was first invented in 1921 by a medical student John Larson and a police officer in California.
The testing procedure takes place as follows.
- First, the examiner asks a few questions to the person to gain some basic information from which he can ask further during the test.
- The sensors are attached to body that continuously record various body rates such as pulse rate, pressure rate, body movement rate.
- Then the real questioning starts. This phase is divided into three categories: 1) irrelevant questioning 2) diagnostic questions 3 relevant questions.
Though the use of the lie detector is restricted, it is used in several counties as a tool for interrogation purposes and preventing security aspects.
One of the destinations that use polygraph in abundance is the United Kingdom. Though many of the European countries do not rely on the polygraph and stating it to be false evidence, UK stands firm in its statement.
The reason many countries are not using this is because there are proven cases in which the guilty people have passed the lie detector test with ease. When asked how they cleared the test, all of them gave a simple answer- “Confidence”. It concludes that, at times even the lie detector can be fooled. Some of the famous London polygraph are NADAC Company, London polygraphs, Lie detector test, north london detectives, lie detectors-uk, uk lie detector test, etc.
These are the private companies that provide assistance for lie detection at a reasonable price for various circumstances.