Polygraph tests are taken by many judicial systems, attorneys, and even employers to check if you are lying or not while answering important questions. Polygraph has been accepted by many courts but recently it has come under a lot of criticism because it tests for an arousal in your feelings and not if you are lying or not. 
The lie detector test or the polygraph test consists of a device which tests the levels of skin conductivity, breathing patterns and your blood pressure. It has certain devices attached to your body while someone asks you the questions even though nowadays many tests are computerized. You are asked questions and the reaction of the various questions is noted on a graph.
HOW TO ACE A LIE DETECTOR TEST?
There are a couple of ways to cheat a lie detector test and one of the most secure ways is to take a medicated drug that will calm your nerves involuntarily during the test but you can’t be doing that if you they have planned to take a drug test before the polygraph test. Then you will have got to get yourself ready for the polygraph test and doing that will require a bit of research.
We have done the research for you and as you know the test monitors your heart rate or your pressure so one of the ways to do that is not take any tension. Constantly talk to yourself and remind yourself that you need to keep calm. Calculate your breathing; remember to leave out at least 30 breaths in a minute with no deep breaths because deep breaths will show up on the graph. You have to practice all these points and take the test day as an examination day. Answer the control questions vaguely or answer them with too much emotion as they will set the tone for the rest of your exam. Don’t come under any effect of the examiner and don’t consider anything that he says.