How to make a homemade lie detector?

Question

I'm doing a project at school and I want to make a lie detector if you know how please tell me

Answer 1

Well ..

How difficult do you want to make this project?

Decide what you want to measure:
Temperature,
Pulse,
Respiration,
Blood Pressure,
and the sweating or dryness of the skin on the palms of the hands,
these are the most common parameters.

The output from sensors that pick up these measurements must then be readable, in real time, while you ask questions; or you need to record both the questions and the output together to analyze later.

Sensors that feed their output continuously to a digital connection (such as a USB or other PC connection), would be best for a homemade system, because you can use the PC to record questions and responses and the simultaneous measurements.

Temperature can be a thermometer with LED readout, or PC input. There are some really nice digital output sensors that measure temperature from a distance, too.

Pulse and respiration need to be motion sensitive sensors, which can be attached to a person (on the wrist and around the chest), and which can be calibrated to produce the correct output signal.

Blood pressure can be done with many home medical BP kits, and some feed directly to a PC.

The easiest is the skin galvanometer, which can easily be made from a low-cost analog or digital multimeter. Many of the digital types now have USB connections and software so that the PC connections are a snap.

You can measure one or all of these parameters, just be sure to research the different response levels of each parameter you measure.

You may have to find software which will allow you to make simultaneous sound and sensor input recordings on a PC, but it should be out there.

Good Luck.

Answer 2

Ask your mom how she knows when you are lying. I have found that to be the best lie detector around!!

Actually there is a term called a "tell" Most people will do something when they lie. As an example: they might lick their lips or look to their right.

Answer 3

Put in the web "lie detector" and you will have a lot of websites.