Engineering Dictionary

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An alphabetical listing of General terms and items.

Radiation   Dico Tools
See Infrared

Rampart   Dico Tools
An enbankment of earth which was used for the purpose of defence, excavated from the ditch, and either raised on the inside or outside of the ditch. A number of different types of ramparts have been employed, generally they surrounded a fortification and were usually topped by a parapet. Dump or Glacis rampart; was the simplest method of constructing a rampart, by excavating a ditch and casting the soil inwards to form a `dump'. Often reinforced by a wall or palisade along the top. Revetted earthen rampart

Rams Horns   Dico Tools
A low work constructed in the ditch in the shape of circular arc, invented by M. Belidor, which were used instead of tenailles.

Randhausburgen (Surrounding-house-castle)   Dico Tools
A German castle with the parts of the castle built around a court (ie. Eltz, Germany, 12th  16th century).

Random Access Memory (RAM)   Dico Tools
Memory that can be both read and changed during computer operation. Unlike other semi-conductor memories, RAM is volatile-if power to the RAM is disrupted or lost, all the data stored is lost.

Range   Dico Tools
Those values over which a transducer is intended to measure, specified by its upper and lower limits.

Rangeability   Dico Tools
The ratio of the maximum flowrate to the minimum flowrate of a meter.

Rankine (R)   Dico Tools
An absolute temperature scale based upon the Fahrenheit scale with 180 between the ice point and boiling point of water. 459.67 R = 0 F.

Rate Action   Dico Tools
The derivative function of a temperature controller.

Rate Time   Dico Tools
The time interval over which the system temperature is sampled for the derivative function.

Rath   Dico Tools
An Irish earthwork fortification dating from the Iron Age.

Ratiometric Measurement   Dico Tools
A measurement technique where an external signal is used to provide the voltage reference for the dual-slope A/D converter. The external signal can be derived from the voltage excitation applied to a bridge circuit or pick-off supply, thereby eliminating errors due to power supply fluctuations.

Ravelin   Dico Tools
A detached outwork developed from the demilune, consisting of a triangular work with two embankments raised before the counterscarp, the work itself was isolated in the ditch of moat. One purpose of the ravelin was to shield the entrance to a fortification from direct bombardment. The ravelin was accessible either by a drawbridge if it formed a part of the road system of a fortification, or if only part of the defence works access was by a tunnel or timber bridge from the inner works. See demilune. (It. ravellino).

Re-entering Angle   Dico Tools
An angle formed by a line of fortification with its apex turned away from the besiegers and towards the centre of the place.

Re-entering Place Of Arms   Dico Tools
An assembly area for troops and munitions in the space left by the re-entrant angle of the counterscarp of the ditch, used to break up an enemy's initial attack or for a sorty against the enemy's lines. Dating form the late 16th century. See place of arms.

Re-entrant   Dico Tools
An inward facing angle, opposite to a salient.

Read Only Memory (ROM)   Dico Tools
Memory that contains fixed data. The computer can read the data, but cannot change it in any way.

Real Time   Dico Tools
The time interval over which the system temperature is sampled for the derivative function.

Record   Dico Tools
A collection of unrelated information that is treated as a single unit.

Recovery Time   Dico Tools
The length of time which it takes a transducer to return to normal after applying a proof pressure.

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Rectangular Buttress Turret   Dico Tools
The rectangular shaped flanking turret which only projected a small distance from the four corners of a Norman rectangular or square keep. See corner buttress turret.

Redan, Reden   Dico Tools
(1) A field work consisting of two faces and an open gorge. (2) A triangular work situated forward of the main fortification, consisting of two faces and an open gorge, like but larger than a flche. Used to fortify walls when the necessity and expense of constructing bastions wasrequired. A system of fortifications using redans produced a series of serrations, the distance between the redans should not exceed the length of musket shot, so that fire from the faces of a redan will be able to the salients of the neighbouring redans. (Re + L. den, tooth).

Redoubt, Redout, Reduit   Dico Tools
(1) A small work placed beyond the glacis, but within musket shot of the covert way, made in various forms, known as a detached redoubt. (2) A small work built in a bastion or ravelin of a permanent fortification. (3) An outwork or fieldwork, square or polygonal in shape without bastion or other flanking defences, sited at a distance from the main fortification, used to guard a pass or to impede the approach of an enemy force.

Redox Potential   Dico Tools
The potential developed by a metallic electrode when placed in a solution containing a species in two different oxidation states.

Reference Junction   Dico Tools
The cold junction in a thermocouple circuit which is held at a stable known temperature. The standard reference temperature is 0 C (32 F). However, other temperatures can be used.

Reference Mark   Dico Tools
Any diagnostic point or mark which can be used to relate a position during rotation of a part to its location when stopped.

Reference Plane   Dico Tools
Any plane perpendicular to the shaft axis to which an amount of unbalance is referred.

Refractory Metal Thermocouple   Dico Tools
A class of thermocouples with melting points above 3600 F. The most common are made from tungsten and tungsten/rhenium alloys Types G and C. They can be used for measuring high temperatures up to 4000 F (2200 C) in non-oxidizing, inert, or vacuum environments.

Register   Dico Tools
A storage device with a specific capacity, such as a bit, byte or word.

Reinforced Concrete   Dico Tools
concrete with steel bars or mesh embedded in it for increased strength in tension; in pre-tensioned concrete, the embedded steel bars or cables are stretched into tension before the concrete hardens; in post-tensioned concrete, the embedded steel bars or cables are stretched into tension after the concrete hardens

Reirata   Dico Tools
A temporary earthen rampart, which was raised behind a breach in a main wall, used to seal a breach.

Relais   Dico Tools
An area at the base of a rampart and the top of the ditch, which was used to collect any earth which eroded from the face of the rampart.

Relay (Mechanical)   Dico Tools
An electromechanical device that completes or interrupts a circuit by physically moving electrical contacts into contact with each other.

Relay (Solid State)   Dico Tools
A solid state switching device which completes or interrupts a circuit electrically with no moving parts.

Relieving Arches   Dico Tools
A 13th century development in the masonry of curtain walls, consisting of wide relieving arches which were keyed into the towers on either side. The arches were intended to counteract the effect of sapping, for even if the base of the wall was destroyed, the wall itself would still be supported by the relieving arches.

Remblai   Dico Tools
The earth which was used to construct a parapet, rampart, etc., of a fortification, which was taken from the ditch when it was excavated. (Fr. remblayer, embank).

Remote   Dico Tools
Not hard-wired; communicating via switched lines, such as telephone lines. Usually refers to peripheral devices that are located a site away from the CPU.

Renketsukei   Dico Tools
A Japanese castle dating from around 1600 A.D., which was formed of three defensive compounds arranged in series along as axis, and connected by gateways. The three compounds were known as; the honmaru, the ninomaru and the sannomaru.

Renketsushiki Tenshu   Dico Tools
The most ornate and complex type of tenshu or principal tower of a Japanese castle, the tenshu was connected to smaller towers by parapets a the corners of the rectangular stone base. See tenshu.

Renritsushiki Tenshu   Dico Tools
A principal tenshu or tower of a Japanese castle which was attached to a secondary tower by a connecting parapet. See tenshu.

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Repeatability   Dico Tools
The ability of a transducer to reproduce output readings when the same measurand value is applied to it consecutively, under the same conditions, and in the same direction. Repeatability is expressed as the maximum difference between output readings.

Reserved Word   Dico Tools
A word that has a defined function in the language, and cannot be used as a variable name.

Residual (Final) Unbalance   Dico Tools
Residual unbalance is that unbalance of any kind that remains after balancing.

Resistance   Dico Tools
The resistance to the flow of electric current measured in ohms (1/2) for a conductor. Resistance is function of diameter, resistivity (an intrinsic property of the material) and length.

Resistance Ratio Characteristic   Dico Tools
For thermistors, the ratio of the resistance of the thermistor at 25 C to the resistance at 125 C.

Resistance Temperature Characteristic   Dico Tools
A relationship between a thermistor's resistance and the temperature.

Resolution   Dico Tools
The smallest detectable increment of measurement. Resolution is usually limited by the number of bits used to quantize the input signal. For example, a 12-bit A/D can resolve to one part in 4096 (2 to the 12 power equals 4096).

Resonant Frequency   Dico Tools
The measurand frequency at which a transducer responds with maximum amplitude.

Response Time   Dico Tools
The length of time required for the output of a transducer to rise to a specified percentage of its final value as a result of a step change of input.

Response Time (time Constant)   Dico Tools
The time required by a sensor to reach 63.2% of a step change in temperature under a specified set of conditions. Five time constants are required for the sensor to stabilize at 600 of the step change value.

Retiracle   Dico Tools
A re-trenchment consisting of two faces which form a re-entering angle.

Retirade   Dico Tools
An alteration to the face of a long bastion large enough to enable a few troops to fire on an enemy trying to gain the re-entrant angle of the ditch.

Retirata   Dico Tools
(1) A work built behind a bastion so as to its strength. (2) An earthwork rampart, raised behind a breach, to enable the garrison to defend the position against storming. See retrenchment.

Retired Flank   Dico Tools
A flank set back or turned inwards to the rear of a work, such as a bastion where the shoulder or orillion protects the guns situated in the flank which were used to enfilade along the curtain. See flank.

Retrench   Dico Tools
To construct an inner line of defence, usually consisting of a trench and a parapet.

Retrenchment   Dico Tools
(1) An inner line of defence, often built behind a breach. See retirata (2). (2) An inner trench and parapet provided against the loss of the outer defences.

Reveal   Dico Tools
An opening in a parapet which has the same purpose as a crenel. See crenel, embrasure.

Revet   Dico Tools
To provide revetment.

Revetment   Dico Tools
(1) A strong retaining wall constructed on the outside of a fortification's earthwork rampart and parapet, so as to prevent it falling into the ditch. (2) The covering of an earthen rampart to prevent it form deteriorating, using such materials as; stones, masonry, concrete or faggots. See demi-revetment, gazion, rampart.

RFI   Dico Tools
Radio frequency interference.

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Rheostat   Dico Tools
A variable resistor.

Richter Scale   Dico Tools
Used to measure the magnitude of an earthquake; introduced in 1935 by the seismologists Beno Gutenberg and Charles Francis Richter

Ridge   Dico Tools
The crest of the glacis.

Rigid   Dico Tools
(adj.) ability to resist deformation when subjected to a load; rigidity (n.) the measure of a structure's ability not to change shape when subjected to a load

Rigid Rotor   Dico Tools
A rotor is considered rigid when it can be corrected in any two (arbitrarily selected) planes [see "Correction (Balancing)Plane"] and after that correction, its unbalance does not significantly exceed the balancing tolerances (relative to the shaft axis) at any speed up to maximum operating speed and when running under conditions which approximate closely to those of the final supporting system.

Ring Wall   Dico Tools
A stone wall which replaced the timber palisade surrounding the summit of a motte of a motte and bailey castle. Also known as a shell keep.

Ringwork   Dico Tools
An earthen defensive enclosure, regardless of period, size or function.

Risban   Dico Tools
A fortification used for the defence of a port or harbour.

Rise Time   Dico Tools
The time required for a sensor or system to respond to an instantaneous step function, measured from the 10% to 90% points on the response waveforms.

Rocco   Dico Tools
An Italian castle or fort which served primarily a military purpose. See castello.

Rock Tunnel   Dico Tools
a passage constructed through solid rock

Role Top Merlon   Dico Tools
A merlon which was designed originally to stop arrows and other missiles glancing of the merlon and passing over the parapet. The design was later used to decorate castellated buildings of the 19th century. See merlon.

Room Conditions   Dico Tools
Ambient environmental conditions under which transducers must commonly operate.

Root Mean Square (RMS)   Dico Tools
Square root of the mean of the square of the signal taken during one full cycle.

Rotor   Dico Tools
A rotor is a rotating body whose journals are supported by bearings.

Round Bastion   Dico Tools
A wide diameter low lying round bastion which was used in the Tudor artillery forts, provided with gun ports and hand gun embrasures, but dead ground was a problem in front of each bastion. See artillery fortress.

Round Gun Turret   Dico Tools
An outwork built on a circular plan and provided with embrasures, situated in the ditch or moat, dating from the 15th century.

RTD   Dico Tools
Resistance temperature detector.

Rutba (Marsad)   Dico Tools
Small isolated fortification along the main roads for military traffic of Andalusia

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