Lie great number of lies, depending on how the political wind blows." The question of whether lies can reliably be detected through nonverbal means is a subject of some controversy. Polygraph "lie detector" machines measure the physiological stress a subject endures in a number of measures while he/she gives statements or answers questions. Spikes in stress are purported to indicate lying. The accuracy of this method is widely disputed, and in several well-known cases it was proven to have been deceived. Nonetheless, it remains in use in many areas, primarily as a method for eliciting confessions or employment screening. Polygraph results
Gaseous ionization detector cannot measure the energy of the radiation (no spectrographic information), it will not measure high radiation rates due to dead time, and sustained high radiation levels will degrade fill gas. The UK Health and Safety Executive has issued a guidance note on the correct portable instrument for the application concerned. This covers all radiation instrument technologies and is useful in selecting the correct gaseous ionisation detector technology for a measurement application. Ionization-type smoke detectors are gaseous ionization detectors in widespread use. A small source of radioactive americium is placed so that it maintains a current between two plates that effectively