Indirect measuring methods
The measured value sought is established by converting the measured variable sought into another measurable physical variable which provides an unambiguous description of the measured variable based o
Impeller
Hydraulic pump which operates in accordance with the hydrodynamic principle (centrifugal pump) and is used as a filling pump for hydrostatic pumps, particularly variable pumps (Figure I 3) . Advantage
Fluid mechanics
Concerned with the physical characteristics and behaviour of fluids at rest (hydrostatics) and when moving (hydrokinetics)
Position measurement
when measuring the length of a path travelled. For path or position measurement, the location of a point is measured in relation to a fixed point of reference. In measurement technology position measu
Vertical column pressure gauge
Pressure gauge that operates based on the principle of the comparison of a pressure with the barometric pressure of a column of fluid (Figure F 23) . They are only suitable for measuring low pressures
European circuit board
Standardised dimensions of a printed circuit board of 100 x 160 mm for mounting all necessary electronic components for a control or a part of a control. The European circuit board is used to standard
Plug-in valve
Valve on which the housing is in the form of a cartridge and with port openings that are aligned with the ports in the installation space (e.g. 2-way plug-in valve).
Pressure fluctuation
Randomly changing pressure between two defined limits (DIN 24 312).
Sealing set
Combination of several individual seals with a pressure ring and a support ring to improve the sealing action. Sealing sets are predominantly used in this form as rod seals. For piston seals in genera
Expandable hose
Hose that is designed such that - unlike a normal hose - it expands a relatively large amount under pressure (Figure D 8) . In this way it is particularly suitable for removing pressure peaks and pres