The Lie Detector Test

General Information

A polygraph examination is the Psychophysiological detection of deception. This means that the mind (psyche) controls the body and when a person tells a lie the unconscious part of their mind affects their body, it is these changes that the polygraph monitors.

A polygraph can literally be broken down like this. Poly means ‘many’ in Greek and Graph means ‘chart’ quite literally it means ‘many charts’. A trained polygraph examiner of good standing (I.E a member of the British Polygraph Association) then uses these charts to determine whether or not there has been any deception.

 Each graph is an exact representation of what each of the sensors (as listed below) is monitoring. A polygraph examination usually lasts between 2-4 hours and consists of a pretest interview, the data collection during the test, the analysis of the data and followed up by a post-test review.


The pre-test interview is usually where we spend the most of our time discussing the issue at hand as well as explaining briefly how a polygraph works along with each of the components. We will also complete any necessary paperwork and will also go over the questions to be asked numerous times!

At no point will an examinee be asked a question that has not been fully reviewed with them. Each question will be asked so that only a simple yes or no answer can be given. All the questions will be reviewed so there is absolute clarity between the examinee and the examiner regarding what each question means.

All polygraphs have audio and visual recordings. This is to ensure that both parties conduct themselves in a professional manner and they may also be used for quality control and/or training purposes.


Electrodermal Activity (EDA)

Electrodermal Activity (EDA)

The galvanic Skin Response is a measure of the change in the examinee’s sweat glands. It is measured using 2 finger cuffs that usually go around the examinee’s index and ring fingers.



The Pneumograph is a measure of the examinee’s respiration and movement. It is measured using two tubes. These go around the examinee’s upper torso and around their abdomen.



The Cardiosphygmograph (more commonly know as a blood pressure cuff) measures the change in the examinee’s heart rate and blood pressure. It is almost identical to the blood pressure cuff a doctor would use.



The Plethysmograph is a sensor that is also connected to either a finger or thumb. It measures the change in blood density in the examinee’s extremities.

Lie Detector Test

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Although our head office is in Essex, we operate throughout the UK, and can carry out tests at short notice in all major cities of the UK. I undertake tests relating to all types of issues including fraud, abuse and infidelity. I am available 7 days a week and take calls from 8am up until 10pm every day. Get in touch  today for a no-obligation consulation, where one of our team will be happy to guide you through the process and advise on the best way forward to finally getting that piece of mind and move on. All enquiries are dealt with compassionatly and in the strictest of confidence.The Lie Detector Test.




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