# Weights and measures [D]

Weights and measures [D]

Dactyl: Linear measure used by the ancient Greeks, which had approximately a finger phalanx, little more than 8 lines.

Date: Measurement of length, also Greek = 0.019 m.

Decade: measure of time, used by the Egyptians, who divided the month into decades = 10 days. It is also equal to 10 years. In ancient Greece, the set of 10 soldiers was called a decade.

Decastereo: Volume measure = 10 m³

Decempeda: Length measure of ancient Rome = 2,962 m.

Decade: conventional measure of time = 10 years.

Decibel: this unit is equivalent to a tenth of a bel or bel (unit of invincible sound.

Decibel: practical measure of comparison between two electrical powers or, also, between two acoustic powers = 0.1 bel. A pair of powers are one decibel apart when they are in the ratio 1:1.26.

The decibel is used as an absolute unit of power, referred to some level of arbitrary choice; the use has become widespread, mainly the following:

Telephony: level 0 = 1 milliwatt.

Radio circuit: level 0 = 6 milliwatts.

One decibel = 0.115 neper.

Finger: ancient measure of Roman origin = ¼ span = 0.111 m. In the past, it was = one of the 48 parts into which the Castilian vara is divided. Record other differences: = to the twelfth part of the span = 9 lines. In Spain = 0.0174 m; in Greece = 0.019 m, in Rome = 0.018 m.

Destre Mallorquín: Spanish measure of length = 4.214 m and surface area (in Mallorca) = 17.1578 m²

Ardura day: Spanish agrarian measure, typical of Asturias = 18,788 a.

Ox day: Spanish agrarian measure, typical of Asturias = 12.577269 a.

Digitus: Greek measure of length = 0.018 m (= width of 1 finger).

Dilochos (Dilodros): Ancient Greek itinerary measure = 12 stadia = 2.222383 km = which was later the Gallic mile in the Roman Empire.

Dyna: Equivalent to a force capable of printing an acceleration of one cm per second to the gram-mass = 1.01937 milligrams force = 10 ^{-5} newton = 10 ^{-8} stenium. In practice, its multiples are used, of which the most used are: The megadyne = 10 ^{-6} dynes. The kilogram force = 981 10³ dynes and the newton = 10 ^{5} dynes and its divisor, the millidyne = 0.001 dyne.

Drachma: ponderal = to the eighth part of an ounce = 3 scruples = 2 adarmes. Liquids = 60 drops. In Egypt = 0.0031 kg and in Austria = 4 pfening = 4.375 g.