Weights and Measures [O]
Obolus: Unit of weight, used for medicines = 3 siliques = ½ scruple = 12 grains = 0.5995 grams. In ancient Greece = ⅙ part of 1 drachma.
Obrada: Agricultural measure of weight. It is equivalent to the work that a man, a pair of oxen or mules do in a day’s work, plowing the land.
In Asturias and Valencia = 53.832 yrs, in Segovia = 39.407006 yrs, and in Valladolid = 46.584278 yrs.
In ancient Greece = 4.10 adarmes.
Ochava: Spanish measure of capacity for oils. In Alava and Vizcaya = 0.0674 litres.
Ochava: Unit of weight (monetary) = 3.6 grams = 75 grains = 6 tomines.
Eighth: Unit of weight for precious metals = 3,594 grams. It also appears as a measure of capacity = 4 skeins = 1,156 liters.
Ochavillos: Spanish measure of capacity for aggregates = 0.2891 litres.
Ocque: Greek weight = 400 drachmas = 1,282 kg.
Eighth: Ancient measure of time used by the Romans = 8 calendar days in duration.
Eighth: Spanish measure of weight = 3.875 grams.
Odrel: Spanish measure of capacity for oil. In the Canary Islands = 48,663 litres.
ohm (Ω): SI derived unit The ohm is the electrical resistance that exists between two points on a conductor when a constant potential difference of 1 volt, applied between the two points, produces a current of 1 ampere in that conductor, not this conductor being the source of no electromotive force.
Olla: Spanish measure of capacity for wines. In Orense = 144 cups = 36 quarts = 9 azumbres.
Ounce: Measurement of length and weight. Ancient = 1/12 part of the Roman foot.
In Argentina (pharmacy) = 8 drachmas = 28.75393 grams.
In Spain = 8 drachmas = 16 adarmes = 28.7 grams = 576 grains.
Medicinal = 28.75393 grams.
Gross weight = 1/18 pound = 29.6111 grams.
Subtle weight = 1/12 pound = 44.4167 grams.
Avoir ounce: 28.349 grams = 437.5 grains = 0.911458 troy ounce.
Fluid ounce: 29.57 mm = 1.8047 in³ = 32 grams = 29.5739 cm³ = 0.0295 liters.
Troy ounce: 31.104 grams = 1.09714 avoir ounce = 480 grains (troy).