Liq′uid-me′ter.
A device for ascertaining the quantity of liquid received or discharged through an orifice.
See meter, water.
It does not appear to have been in use prior to 1824, when William Pontifex of
London,
England, patented a new mode of adjusting or equalizing the pressure of fluids or liquids in pipes or tubes, and also an improved mode of measuring said fluids or liquids.
This consisted in forming a chamber over the supply-pipe and near its end, in which was a leathern cup secured to the top of the chamber.
A series of weights, one above the other, was also suspended from the top of the chamber, which were successively raised as the pressure of the liquid increased.
An arm connected with the bottom of the
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cup operated a valve, which gradually closed the discharge orifice as the weights were lifted.
William Brunton, near the same time, invented a meter in which the reciprocating motion of a piston in a cylinder was caused to measure the amount of water discharged, the valve arrangements, etc., being similar to those of the steam-engine.
The forms of meter are various, the principal being known as the
diaphragm, the
balanced, in which compressed air is employed, the
piston, the
propeller, and the
flexible tube and roller meter.
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Liquid-meters. |
The spirit-meter of
Siemens and Halske is shown in
Fig. 2970 (
A). This instrument is designed to register the quantity of spirit discharged, and also the amount of absolute alcohol contained therein.
The liquid enters through the pipe
a into the chamber, whence it passes through two pipes
c d, one of which terminates in a chamber
c, whence it is carried by the pipe
f through the lower part of the vessel
g. The other conducts it directly to the upper part of
g.
The parts of the pipes which pass through
g are perforated respectively on the upper and lower sides, causing upward and downward currents therein, thoroughly mingling the spirit, so as to insure that the quantity of alcohol contained in the spirit does not vary.
The two meet in the chamber
h, passing through a pipe
i into a chamber
j, from which it flows into the
volumeter through the pipe
k. The volumeter is a hollow drum
l, having a concentric cylinder
m, the space between the two being divided into three compartments.
Three slits in the central cylinder permit the liquid to flow successively into each compartment, as it in turn occupies the lowest position.
The openings are so arranged that while the lower chamber is filling the level is too low to permit an escape into either of the others, and the apparatus remains stationary until the lower chamber is full.
The discharge of this then commences, while the aperture through which it received its supply is carried by the rotation above the liquid in the central chamber.
To prevent overflow until this change of position has occurred, the discharge-channels are carried spirally from each chamber round the exterior of the one next following.
The registering dials are actuated in the usual manner.
The amount of pure spirit is determined by the indications of a hydrometer
n in the tank
g, having a curved lever, the shorter arm of which is connected with its stem.
The hydrometer is filled with alcohol, and rises and falls according to the density of the surrounding spirit, causing the lever to vibrate each time that a chamber of the volumeter is emptied, to an extent indicating the quantity of pure spirit contained therein.
A three-leaved cam, attached to the axis of the volumeter, is connected with the long arm of the lever, and is provided with a ratchet-wheel of large diameter with fine teeth.
This is placed on the axis of the first register-wheel, and causes it to turn an amount equal to the movement of the curved lever.
The water-meter of Duboys of
Paris (
B) consists of a casing
a, in the interior of which is a diaphragm
b, carrying in its center a metallic disk
c, the convex edges of which accurately fit the sides of the casing.
The diaphragm and disk are kept in position by the rod
d, which passes through water-tight orifices.
c and
f are apertures for receiving and discharging the water.
As the water enters through either duct, as
e, it raises the diaphragm, forcing out the water on the upper side until the vessel is full, when the diaphragm fits closely against that side.
During the process of filling, the vessel is inclined; but when the weight rises to the top, it gives that side the preponderance, causing the vessel to turn on its pivots until it becomes the bottom side.
At the same time, the supply-opening is closed and that for discharge opened, while on the opposite side a contrary effect is produced.
Arrangements are provided to prevent the vessel from tilting until it is entirely filled.
The meter of
M. Clement of
Orleans consists of an upright cylinder divided into five compartments, each of which is caused to actuate a crank on a vertical axis common to all. This carries a compound stop-cock, which admits the water to and discharges it from each compartment when filled.
Payton's meter (
C,
Fig. 2970) contains two S-shaped arms, whose extremities during rotation are in close contact with each other and with the sides of the box. The arrows indicate the direction of the current.
Similar devices are shown under rotary blower ; rotary pump.
In
Cochrane's meter for measuring liquids under pressure, the measurement is effected by a pivoted vessel resembling a double scoop, which tilts and discharges when either side is full.
A bent lever below this is tilted back and forth at each movement of the scoop, actuating the registering mechanism.
Atwell's cylindrical case has a piston
E which turns on an axial shaft communicating motion to the register, and carrying an arm which, at the end
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of each stroke, changes a cylindrical valve
F2 so as to cause the water to alternately enter and discharge from the measuring-chamber at opposite sides of the internal partition
C.
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Pulsating-piston meter. |
In
Fig. 2972, a water-wheel within a pipe is connected to a register to indicate the flow of water.
The flow is regulated by a sliding-valve.
In Young's spirit-meter, floats
G in the measuring-chambers are attached to each end of a pivoted beam.
The alternate downward motion of the floats, as the chambers are discharged, diverts the induction flow from one to the other.
The floats
G and their valves occupy two chambers, and are suspended to opposite ends of the oscillating beam
E. The valve-stems have a limited sliding motion in the floats, so that the float will rise to a sufficient hight without raising the valve to permit the emptying of the chamber.
At the point of discharge the weighted rod
J is thrown past the vertical, and, closing the valve to this chamber, opens the induction-pipe to the other chamber, depressing that float sufficiently to close the escape-valve.
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Spiral-vane meter. |
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Young's spirit-meter. |
In
Sickles's meter (
Fig. 2974) the liquid, flowing into the chamber
D, is by means of the valve
C admitted alternately to each end of the hollow valve
B, which is divided into compartments by the partitions
l l′. From these the fluid flows alternately through appropriate ports behind the pistons
a a on the rod
b, which has tappets that strike the pins
e e′ on the upright shaft
d, causing its partial rotation and operating the slide-valve
C, which admits the fluid into the compartments of the valve
B.
