Process Control Terminology from ONEhalf20

Q

Quiescent Supply Current-the supply current being drawn when the pressure sensor is at null.

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R

Ratiometric (Ratiometricity Error)-at a given supply voltage, sensor output is a proportion of that supply voltage. Ratiometricity error is the change in this proportion resulting from any change to the supply voltage. Usually expressed as a percent of full scale output.

Range-the measurand values over which the sensor is intended to measure, specified by the upper and lower limits.

Rectifier-a device that converts alternating current into direct current.

Reed Technology-technology where the reed contacts are designed to be actuated by a magnet. When a magnetic field is brought close to the reed contacts, the contacts are drawn together to make the circuit.

Reflective Scan-a scanning technique in which the light source is aimed at a reflective surface to illuminate the photosensor. Retroreflective, specular, diffuse scan and convergent beam are all reflective scan techniques.

Regulation %-the ratio of voltage extremes due to loading or line fluctuations. The process of holding constant a quantity such as voltage by means of a system that automatically corrects errors. For example, as more current is drawn from a battery or power supply, the output voltage tends to decrease (load regulation). With a power supply derived from AC, the DC output voltage can vary with the variation in AC voltage (line regulation).

Release Force-the level to which force on the plunger must be reduced to allow the contacts to snap from the operated contact position to the normal contact position.

Release Point-that position of the plunger at which the contacts snap from the operated contact position to the normal contact position.

Release Travel-as an operating characteristic of a switch, release travel is the distance through which the plunger moves when traveled from the release point to the free position. As a characteristic of the actuation applied to the switch, release travel is the distance the plunger is released past the release point.

Repeatability-the ability of a sensor to reproduce output readings when the same value is applied to it consecutively in the same direction, for a specified number of cycles, or specified time duration.

Resolution-the magnitude of output step changes as the pressure is continuously varied over the range. This term applies primarily to potentiometric sensors. Re