Hair tests are more likely to detect regular than occasional marijuana use. One study found that 85% of daily users tested positive for marijuana, versus 52% of occasional smokers (1-5 times per week). Ingested cannabis was less likely to be detected than smoked marijuana [ 01 ].
For the similarly named concept in computer science, see Finite state transducer. A transducer is a device that converts one form of energy to another. Usually a transducer converts a signal in one form of energy to a signal in another. Transducers are often employed at the boundaries of automation, measurement, and control systems, where electrical signals are converted to and from other physical quantities (energy, force, torque, light, motion, position, etc.).
Stereo speakers are a type of transducer. Audio cassettes are created by using a transducer to turn the electrical signal from the microphone pick-up into magnetic fluctuations on the tape head. Ultrasound imaging relies on transducers to convert sound energy into electrical pulses. Many types of electric starters use piezoelectric transducers.