| In its most basic terms, a pressure transducer | | | | on other factors. The type of sensor and type of |
| measures the pressure exerted on its sensing | | | | pressure is one indicator. Absolute sensors test in a |
| mechanism and change it to an electrical signal. They | | | | true absolute vacuum. Gauge sensors test relative |
| are most commonly used to calibrate the pressure | | | | pressure. Differential pressure sensors test the |
| that a gas or liquid exerts under variable conditions. | | | | difference between two or more pressures. And a |
| They are widely used in aeronautics and | | | | sealed sensor is calibrated and then sealed to |
| oceanographic vehicle manufacture. Various types are | | | | measure pressure in terms of a known pressure, |
| made with special conditions in mind, such as | | | | usually at sea level. |
| measuring pressure exerted in a vacuum or when the | | | | Pressure transducers are also classified into two basic |
| gas or liquid is exposed to an extreme range of | | | | categories. The first are the force collectors, which |
| temperatures. The measurements are then recorded | | | | use a bellows, piston, or diaphragm. The second |
| onto data loggers. | | | | category is basically all transducers that are not force |
| For example, the most widely used and economical | | | | collectors, and encompasses thermal and resonant |
| transducer is the strain gauge type. When pressure is | | | | transducers. Strain gauge transducers fall in the |
| exerted on a diaphragm, strain is placed on the | | | | category of force collectors, as are capacitive |
| instrument gauges. This is then converted to an | | | | transducers commonly used to take readings under |
| electrical signal. | | | | low pressures. Piezoelectric transducers, which are |
| The output can take three different forms. Millivolt | | | | often used to test combustion in automobile engines, |
| output transducers are among the least expensive | | | | are also force collectors. The resonant and thermal |
| type. They are most useful when the distances | | | | transducers check the density of a test gas while |
| involved are short and the environment does not | | | | under pressure, and are often used to take multiple |
| feature a lot of electrical noise. A consistent power | | | | readings over an extended length of time. |
| supply is necessary for the most accurate readings. | | | | Anyone asking, "What is a Pressure Transducer?" |
| Voltage output pressure transducers are less | | | | may also wonder about some of their applications. |
| susceptible to electrical noise. The power supply is | | | | They are important tools to manufacturers of |
| also not as important as with millivolt transducers. | | | | aircraft, automobiles, weather instruments, and |
| The final type of output is a 4-20 mA output | | | | satellites. From rockets to weather balloons, pressure |
| pressure transducer, sometimes called a pressure | | | | transducers are used to measure the effects of |
| transmitter. These types are often used when lead | | | | changes in air pressure. They are also used to help |
| wires must span a long distance. Least susceptible to | | | | submarines measure depth. In addition, several |
| electrical noise and power fluctuations, these types | | | | industries use them to test pressurized systems for |
| can utilize lead wires of around 35 yards or more. | | | | leaks. |
| Pressure transducers are further categorized based | | | | |