Introducing Polygraph lie detector in Singapore investigation

Polygraph machine or the lie detector is a device to monitor the physiological reactions in a person. The instrument is mostly used in Singapore investigation in the police departments, private investigation companies and other investigation companies. The machine is very popular in recent times. The detector or the machine acts as a saviour to the investigation companies. It helps them to identify the culprits with weak and fragile nature. The significant involuntary response in a person is identified. Stress level of the person is another criterion which is tallied.  Deceptive behaviour along with stress is captured in the device. If you want to look at the history of polygraph lie detector machine, it was invented by James Mackenzie in the year 1902. But the machine lost its shine when a modern kind of instrument was invented by a medical student, John Larson. Since 1924, the machine has been used for interrogation by police and private investigation companies. The computerized polygraph lie detector consists of a computer system, a coupling element that renders a strengthening of the physiological indicators and their conversion to digital form and printer. Psychologists have been discussing its disadvantages from its existence. It is due to the false interpretations made because of the fear factor and not because the person has lied or did a crime. The working of the machine is a series of different sensors attached to the body which is measured as physiological changes in a person. In a polygraph test, four to six sensors are fixed on the body of the person. Multiple signals from the body are taped on a paper.
In Singapore investigation breathing rate, pulse rate, blood pressure and sweating is recorded in the test. The movements of the person are also manually recorded by the examiner. The movements are recorded with the constant questioning. The questions are set aside according to the case. All the movements and signals are counted throughout the questioning. The critical changes in the graph or the paper are seen from the responses. A psychologist can infer out of the responses and the graph. The critical evaluation of the responses can make the examiner come to a conclusion. The questions are subjective to the case. The machine is based on skin resistance changes when the person sweats profusely. The machine needs a tuning while working in a person. The tuning is done as per the difference in the skin texture. The tuning control is adjusted in a way that the red light is dimmed. It is tuned according to the skin tone. When a person tells a lie, the red light gets brighter when the sweating increases.
Sometimes in Singapore investigation the polygraph lie detector can lose the confidence of investigation committee in it. It is because people can excel to counter the questions. The person can be relaxed during the examination process. The machine only detects lies or the fear in a person. There are counter actions which will not be registered in the response sheet of the machine. If the criminals can make a crime intelligently, then why not excelling in a polygraph test. Hence the use of lie detector should be used carefully and with the right kind of person. The investigation process is handled perfectly by the police or private investigation companies. Then the person to be examined in a lie detector should be studied well before a sitting in the lie detector. The polygraph exam has been used extensively to solve many crimes. Therefore the criminals are aware of the spoofs and techniques to overcome the signals to the machine. The interrogation with the lie detector can be a boon or a bane in the investigation.