Hall effect sensor
independently of the rate of change and also over quite large distances. Their accuracy is ±0.2% based, for example, on a measurement range of 0 to 250 mm.
Volumetric efficiency
describes the ratio of the effective (actually absorbed or issued) flow rate to the theoretical flow rate based on the displacement kinematics and the rotation speed. For pumps: Effectively delivered flow rate
Measurement uncertainty
breadth of this interval! ( Figure M 22 ) (as per DIN 1319). Figure M 16 shows these relationships based on the example of possible errors associated with a position measurement system.
Bode diagram (frequency characteristics)
graphically as a function of the logarithm of the circular frequency ω or the frequency f (Figure B 22) . Based on the Bode diagram for a controlled subsystem it is straightforward to find a controller with which
Operational amplifier
output resistance. The operational amplifier always operates on the principle of negative feedback based on impedance (mostly involving a resistor or capacitor) whereby connecting various impedances results
Hagen-Poiseuille's law
Describes the flow rate through laminar flow resistors ( capillary tube , gap). It is assumed, based on a steady-state laminar flow and a constant cross section flow, that the compressive force will be
HFC pressure fluids
Fire-resistant fluids based on a solution of polymers (polyglycols) in water at a ratio of around 60:40. HFC pressure fluids have a viscosity of 30 to 45 mm2/s at 50°C and may be used instead of mineral
Selsyn rotary position encoder
Electromagnetic position encoder based on the principle of the rotating field that contains a rotor and a stator with a number of windings and with an output voltage that corresponds to the angular position
Indirect measuring methods
another measurable physical variable which provides an unambiguous description of the measured variable based on physical correlations. In other words, the output is expressed in variable values associated with
Piezoresistive pressure sensor
Pressure transducer based on the piezoresistive effect whereby pressure causes an elastic semiconductor structure to change, which in turn changes the values for resistances connected as a Wheatstone bridge