Glossary Q – S

*terms marked with an asterisk appear in this glossary

QUADRANT SCALE — a scale of the pendulum type* which incorporates a quarter segment of a ring to carry the graduations.* The quadrant may be fixed or may move with the beam and is used with a pointer.* The name is usually used to describe a paper scale, Fig. 50. There was also a spring balance made by Geo. Salter & Co., registered in 1869, which was called a Quadrant Balance, Fig. 56. (NB: a 1/6 segment is a sextant, and 1/8 is an octant.) 

QUINTENZ SCALE — see DECIMAL SCALE. 

R.A. — Recht Abgezogen (German) = properly adjusted. These initials are sometimes found on boxes of coin scales and weights. See also A.G.

RACK-AND-PINION — a toothed rod and gear wheel used to convert linear motion to rotary motion, as used for the pointer* of dial-face spring balances, Fig. 52. 

RATIO — see LEVER RATIO. 

READING EDGE — the edge of a poise* which is used as an index* for reading weight graduations. Also called a FIDUCIAL EDGE on old English grain scales.

RELIEVING GEAR — a mechanism which removes all the knife edges* from their bearings to prevent unnecessary wear or damage, Fig. 53. Mainly used on precision balances* and platform scales.* See also ARRESTMENT GEAR. 

RESISTANT — that part of a scale that counterbalances the load, e.g., weights, spring, pendulum weight, sliding poise, liquid, etc. 

REVERSIBLE STEELYARD — see TURN-OVER STEELYARD.

RIBBON — see BAND. 

RIDER BAR — a graduated bar attached to the side of a scale beam for use with a small traveling rider weight,* on Precision balances Fig. 53.

RIDER WEIGHT — a minute poise* used on a rider bar* and usually made of bent wire, Fig. 53. It is normally moved mechanically from outside the case of the precision balance,* and its use eliminates the need for small loose weights. 

RING-AND-HOLE END — a beam end pivot where the ring passes through a hole in the end at 90° to the beam. It was used by the Romans, and by many simple civilizations up to the 20th century, Fig 6 No.3 (Glossary A–C).

ROBERVAL SCALE — a scale constructed on the principle invented by Giles Personne de Roberval. It was first used for scales in the early 19th century. The load and weight plates are placed above the beam supported by a system of legs* and stays,* thereby eliminating the obstruction caused by the cords or chains of hanging pans, Figs. 1 (Glossary A–B) & 55. Also called a STABILISED PAN SCALE (USA). See also INVERTED ROBERVAL SCALE, BERANGER, PHANZEDER. 

ROCKER BALANCE — a scale on which the load is placed directly on the beam so that it rocks with the beam like a seesaw. The load must be located on the beam exactly, so such a balance is best suited to weighing specific articles of known dimensions, such as coins or eggs, Fig. 54. 

ROCKING HORSE STEELYARD — a form of steelyard where the beam has arms* almost equal in length, and where the sliding poise* moves from one arm to the other, passing over the fulcrum,* Fig. 51. The advantage of such a system is compactness combined with a small mass required for the poise. 

ROD LINKS — rods used to suspend a pan, as an alternative to chains. The rods may be used singly or linked together in twos, threes, or more, Fig. 7b (Glossary A–B). 

ROMAN STEELYARD — the classical design of steelyard with a hanging poise,* Fig. 49, often made in the turn -over pattern.*

SADDLE — a pad or carriage carrying a knife edge* and arranged to slide along a beam to adjust the leverage. Also called a NOSE IRON (USA). Although used as a term for weighing machine parts, the term may be used to describe the carriage carrying the fulcrum* of certain steelyards* and bismars,* Fig. 9b (Glossary A–B). See also SLIDING BEAM STEELYARD. 

SCALE, SCALES, A PAIR OF SCALES — (1) names for a weighing instrument, said to be derived from the old Norwegian SKAL, meaning a bowl. Strictly speaking, a scale is a pan, and it was used in this sense until the 20th century, hence the term "pair of scales" for a balance with two hanging pans. 

SCALE — (2) a series of graduations.* It is strongly recommended that this term not be used to avoid confusion. Instead, the terms GRADUATIONS, DIVISIONS, CHART, or QUADRANT should be used.

SCOOP — a deep receptacle of oval or egg shape used for weighing and pouring-out loose goods, powders, etc.  Figs. 19 (Glossary C–D) & 25 (Glossary E–J).

SEAL — see VERIFICATION MARK.

SECTOR SPRING BALANCE — see 'V' SPRING BALANCE.

SELF-INDICATING SCALE — a scale which indicates the weight of a load automatically, e.g., a spring balance, pendulum balance, Fig.25 (Glossary E–J). See also SEMI-SELF-INDICATING SCALE.

SEMI-SELF-INDICATING SCALE — a scale which indicates part of the load automatically, leaving the remainder to be balanced manually by loose weights, or a sliding poise.*  Fig. 58. 

SEMI-ROBERVAL — see HALF-ROBERVAL.

SENSIBILITY — see SENSITIVITY.

SENSITIVITY — the smallest weight which will cause sensible movement of a scale beam. The sensitivity usually varies with the load, so it is necessary to state the load at which the sensitivity occurs. Also called SENSIBILITY or SENSITIVENESS. 

SHACKLE — a forked bracket containing bearings and used to suspend beams, pans, hooks, etc., or for connecting parts of a scale lever system, Fig. 49. See also SHEARS. 

SHAGREEN — a substance used to cover the boxes for some English coin scales in the 18th century. Said to be made from the skin of a dogfish or made from untanned leather with a deep granular surface formed by pressing seeds into the surface. Shagreen scale boxes are usually black, but the surface may be polished flat and dyed green or red. Also called SHARKSKIN or FISHSKIN.

SHARKEY END — a beam end patented by Patrick Sharkey of Liverpool, in 1853. Agate bearings* are protected in a box-like cover called an AGATE BOX, Fig. 6, No.24 (Glossary A–B).

SHARKSKIN — see SHAGREEN. 

SHEARS — a forked, or two-legged structure carrying the main bearings for the fulcrum* of a scale beam, and which is used to suspend the scales, Fig. 59. Also called CHEEKS, FORKS, or GALLOWS. See also SHACKLE, SIGHT-HOLE SHEARS. 

SHELF EDGE SCALE — a scale that requires the use of a shelf or table edge to support the pivots and to act as a bearing surface. The load is suspended over the edge of the shelf. Patented in England by Hulls and Bradford in 1753. A letter version is shown in Fig. 9b (Glossary A–B).

S-HOOK — a hook shaped like a letter 'S' used to suspend scales, loads, etc., Fig. 67. See also S-LOOP. 

SIDE BEAM — see TARE BAR. 

SIGHT-HOLE SHEARS - shears* with a hole in the legs through which the pointer* can be seen or sighted. Fig. 13 (Glossary C–D).

SINGLE LEVER MACHINE - a scale that uses an unequal-arm beam,* or a loose­ weight steelyard,* with a load receptacle above the beam. The receptacle is stabilized by a leg* and stay.* Fig. 60. 

SLIDE —

1. The flat pillar with a curved top loosely attached to a column* and from which a scale is suspended. The slide is lifted by a lever, or key,* to raise the scales into the weighing position, Fig. 59. 
2.  A sliding poise* used on folding gold balances,* Fig. 61.

SLIDING BEAM STEELYARD — a steelyard on which the main fulcrum* and load shackle* are carried on a saddle.* The beam is also part of the weight and it slides through the saddle. The position of the beam indicates the weight of the load, Fig. 66. See also TELESCOPIC STEELYARD. 

S-LOOP — a wire shaped like a closed letter 'S' used to suspend scales, pans, hanging poises, etc., Fig. 6 (Glossary A–B). See also S-HOOK.

SLOTTED WEIGHT — a weight with a slot formed in it which is designed to fit over a single hanger* rod. Usually, they are proportional weights* for use with a loose-weight steelyard,* Fig. 63. 

SLOW — a scale is said to be 'slow' when the weight indicated is lower than the true weight. Normally, a term used for dial or fan scales.* See also FAST. 

SPECIFIC GRAVITY BALANCE — a scale designed for determining the specific gravity of substances by comparing the weight in air with the weight in water. The specific gravity of liquids is determined by weighing a standard solid body in water and then in the liquid. Balances may take various forms, one of which is shown in Fig. 64. 

SPIDER — a three- or four-legged support for a pan* or scoop.* The legs are longer and more curved than a cross,* Fig. 25 (Glossary E–J). 

SPRING BALANCE — a scale that uses a spring resistant* to balance the load, instead of weights. The spring may work in tension or compression and can take a variety of forms:  coil, 'C', 'V', ellipse, lyre, flat, etc.  Fig. 67. 

STACKING WEIGHTS — weights which rest on top of each other in descending order of weight and located by a shallow rim around the top of each weight, Fig. 65. Also called TELESCOPE WEIGHTS and sometimes referred to in old catalogues as NEST WEIGHTS. It is recommended that the last term not be used.

STAMP — see VERIFICATION MARK. 

STAMPING PLUG — a soft metal plug, usually lead, fixed into a hole in weights and scales, to receive the verification mark.* 

STAND SCALE — a scale suspended from a column* attached to a base, Figs. 7b (Glossary A–B) and 34 (Glossary E–J).

STANDARD WEIGHT — a weight used as a reference for checking other weights or scales.

STAY — a bar connecting the bottom of the leg* to the lower center pivot in a Roberval scale,* or any similar application, Figs. 1 (Glossary A–B) & 36 (Glossary K–P). Also called a CHECK (USA), or an OVERHEAD CHECK on an inverted Roberval scale* (USA). 

STEELYARD — an unequal-arm beam with a fixed fulcrum and a sliding or hanging poise* by which means the load is balanced, Figs. 40 (Glossary K–P) & 49. Also called a STILLIARD, STILLION, STILLERD (Old English) and several other names, or a BEAM SCALE (USA). See also ROMAN STEELYARD, SLIDING BEAM STEELYARD, TELESCOPIC STEELYARD. 

STEM — see LEG.

STIRRUP END — a beam-end suspension component shaped like a stirrup, with a single bearing.* A continuous knife edge* is used with it, Fig. 6, No. 25 (Glossary A–B).

STRAIGHT-FACE SPRING BALANCE — a spring balance with the pointer* attached directly to the end of the spring, and which registers the extension of the spring (weight) on a straight face, Fig. 67. 

STYLUS BALANCE — a device used for measuring the force applied to a record by the stylus of a record player. As the player arm is supported at one end by its pivot, the stylus balance does not measure the weight, it only measures part of the weight. So, although closely allied to balances it is not a true scale. Fig. 68. 

SUBSTITUTION BALANCE — a scale on which the weights are carried on the load arm of the beam counterbalanced by a dead mass on the other arm of the beam. The mass is fixed to the beam, so there are only two knife edges, Fig. 62. When the load is placed in the pan, weights are removed to restore balance. The sum of the weights removed equals the weight of the load. Also called a CONSTANT LOAD BALANCE or a TWO-KNIFE BALANCE. See also SUBSTITUTION WEIGHING. 

SUBSTITUTION WEIGHING — the load to be weighed is placed on one scale pan and balanced with any suitable loose material on the other pan. The load is then removed, and proper weights are substituted for the load until equilibrium is restored. The total of the weights is the weight of the load. Also called BORDA WEIGHING after the French scientist Jean Charles de Borda (1733–1799).

SUSPENSION RING, or LOOP — a ring of wire attached to the top of the shears* or top of a spring balance, etc., used to suspend the instrument, Fig. 44 (Glossary K–P). 

SWAN-NECK END — a beam end curved like the neck of a swan. The turned-down end has a hole filed into a simple form of knife edge. A ring or S-loop* is passed through the hole and is used for the attachment of cords or chains, Fig. 6 No. 7 to 10 (Glossary A–B). See also INVERTED SWAN-NECK END.