A polygraph, or lie detector, is a machine that measures certain types of bio data, such as a person's heart rate, during a series of questioning. The results of this data is believed to reflect the person's measure of honesty while giving their answers.

1,063 Questions

What is the word polygraph in a sentence?

The polygraph test is not "proof-positive".

The polygraph test is not completely unreliable.

How does a lie detector work?

A polygraph (often called a lie detector) is actually a biomedical instrument. This device looks at and charts or logs a number of physiological characteristics (blood pressure, pulse, respiration, breathing rhythm, body temperature and the conductivity of skin) and the changes in these features as questions are asked of the subject and he answers.

The idea is to ask questions that establish a "baseline" physiology. If and when the subject provides false answers, changes in some "baseline" physiological factor will appear. These can provide some distinctive contrasts that could indicate that the individual is lying. The physiological changes monitored are controlled by the sympathetic nervous system, and as the questions are asked and answered, physiological responses are tracked. A link can be found below to check facts and learn more.


A polygraph is a machine in which the multiple ("poly") signals from the sensors are recorded on a single strip of moving paper ("graph").

How does it work?

About 4 to 6 sensors are attached to body parts of a person during polygraph test and the sensors record data from these locations.

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How much are lie detector tests in the north east?

I'm not sure they are offered commercially. I have never heard of such a thing. You can purchase your own polygraph machine ranging from about $900 to $15000.

Where can you buy a polygraph machine?

Polygraph or 'lie detector' machines is a technology is that is still not generally liked or trusted technology. Trained, experienced people make a living from polygraph use is still hard. Talking with some who are already working in the field would be best able to help you

Who invented the Lie Detector?

John A. Larson, who was a medical student in California.

Can you fool a Lie Detector?

there is a possiblility if someone is trained to control the way their heart beats or their pulse rate. It is extremely difficult.There are "tricks" Taking sedatives to calm yourself down, putting a thumbtack in one of your shoes (under your big toe for example) and during the "Test" push your toe down on it....on one of the "LIES" they have you say...this INCREASES the recorded response.....they'll say "Gee..this guy really SHOWS when he lies...he tenses waaay up, when actually you did not, making a REAL lie easier to skate by on.

Look up books online, on the CAN beat these machines...they are FAR from perfect...why do you think judges won't allow them into a courtroom???!

Good luck.

One trick that works is

You can also think of something really exiting when they ask your name the color of the wall and any obis questions like that and when they ask the questions you need to lie on it will show your heartbeat as normal.

Can you become an astronaut if you've used LSD?

LSD only stays in your system for about 24 hours. Even with the advanced testing methods they probably use on potential astronauts it wouldn't be detectable after about two weeks. Check out for more info on this.

Unless they ask you if you have taken it, and they know you are lying. But even then - I am not sure what the astronaut entry requirements are but "have you taken LSD before" may not be such an issue to them. Perhaps it is though, there isn't much point in sending someone up into space if they are already there. There are requirements for doctors certainly but if the review board or whatever doesn't know you did it then they won't punish you for it.

>>>>>To become an astronaut you typically need to be a member of the military. This is not always the case, but regardless of civilian or military you need to qualify for a full-scope top secret clearance. This involves a very intense interrogation (in which the average person WILL admit to illicit drug use if true) and a polygraph, to include questions about illicit drug use. Now a polygraph's reliability is certainly up for debate, however failing one will prevent you from obtaining a clearance. You fail the top secret process and you cannot become an astronaut. So bottom line-can you lie? If yes, you could still become an astronaut.

Are polygraph test 100 percent accurate?

They are 98% true but some people can bet it.

How much will it cost to take a lie detector test and how much is a lie detector instrument?

It depends on the issue. $400 is a starting point. Some polygraph examiners will charge as much as $1500 for a polygraph test.

The instrument is a different story. They're now using computerized polygraphs. The software program and equipment will run around $6K. A used analog instrument will run around $1,200

i think about $400.00

Is a polygraph test inadmissible in court?

I think no.

1980 - United States v. Roberts

The prosecutor had told the grand jury unequivocally that polygraph results were inadmissible in a court of law and the court called her on the carpet and stated that her statememnt was false and said "The Court dissapproves of the prosecutor's bold statement to the Grand Jury that polygraph evidence is inadmissible at trial. Such statements are absolutely untrue. The Ninth Circuit has held that polygraph evidence is admissible within the trial court's discretion."

As current law stands it is up to the trial judge as to how he or she will handle any motion to admit polygraph evidence.and Polygraph tests are regularly admitted as evidence in trials and they are also regularly rejected as evidence in trials....

However Legally in all 50 States of the US you can refuse to submit to a polygraph test and the fact that you refused the test can't be used against youin a court of law..But if you take the test it could be used against you if the trial judge decides to allow it.

Can you fool a polygraph machine?

Knowing the person administering a polygraph for pre-employment once, I asked to be given a second polygraph where I would purposely give false answers. I remained calm and didn't "figit" while giving lies to the questions, and PASSED, so I can say it is least in my case.

What Four major components of polygraph machine?

The four major components that make up a polygraph machine are the pneumograph, galvanograph, cardiosphygmograph, and the kymograph. These components work together to be able to determine if a subject is deceitful of not.

Advantages and disadvantages of the lie detector?

advantage: you come to know who is lying

disadvantage: the principle is based on the human skin resistance, is the person who is subjected to the test is lying confidently then it will be difficult for the lie detector circuit to catch a lie because in this case you wont be sweating or feeling nervous

Where do you go to take a lie detector test?

There are many private polygraph examiners you can go to, but qualifications of an examiner can vary greatly. Make sure the examiner is a member of the American Polygraph Association or the National Polygraph Association and that their continuing education is up to date. If the state requires a license, be sure they have one. You can find a list of private examiners worldwide at

How does the spy net video watch lie detector work?

it senses your stress level and if you are stresses it thinks your lying

Why lie detectors are not used in court cases?

Because people can train themselves to lie, so that their metabolism (the part the machine measures, such as heart rate and skin temperature) does not change when they lie. Also, the machine might not be calibrated accurately.

Does the spy-net watch have a lie detector?

yes the spy-net watch has a lie detector it is cool

If you have to take a lie detector test can you be charged with crimes from your past?

Yes. But lie detector evidence is usually not enough. Also you can not be forced to take one.

You are witness for a burglary who was also involved. Now the police want you to take a lie detector test and will charge you if you refuse. What can you do?

You should speak with an attorney who specializes in criminal law in your area. On the other hand you can wait until you have been charged and then request that an attorney be appointed for you.

How much a fidelity polygraph test cost?

A polygraph test test can cost anywhere from $400.00 to 600.00 that would be according to what state or country you live in.