Generally speaking, the price of the meter is a subordinate consideration.
A more modern type of electrolytic meter is that due to C. O.
The first electrolytic house meter in connexion with public electric supply was described by St.
It consisted of a glass vessel, containing a solution of sulphate of zinc, in which were placed two plates of pure amalgamated zinc. These plates were connected by means of a german-silver shunt, their size and the distance between them being so adjusted that about ii 0 - 0 - part of the current passing through the meter travelled through the electrolytic cell and -j o i j of the current passed through the shunt.
Owing to the cost and trouble of weighing a large number of zinc plates, this type of meter fell into disuse.
In the Long-Schattner electrolytic meter a solution of sulphate of copper is electrolyzed.
In its improved form this meter consists of a single horseshoe permanent magnet formed of tungsten-steel having a strong and constant field.
The principle of the meter is to make the breaking and driving action so strong that the friction of the train becomes immaterial in comparison.
- A gas meter which has an error of more than 2% in favour of the seller or 3% in favour of the customer is not passed for use.
An electricity meter should therefore have approximately the same accuracy.
The accuracy of a meter is tested by drawing calibration curves showing the percentage departure from absolute accuracy in its reading for various decimal fractions of full load.
With a supply pressure of 200 volts a 5 c.p. carbon filament lamp takes only 0.1 ampere; hence unless a meter will begin to register with 1 1 - 6 - ampere it will fail to record the current consumed by a single small incandescent lamp. In a large supply system such failure would mean a serious loss of revenue.
ABD, is termed a " segment "; if the chord be a diaD meter, the segment is termed a " semi D A circle."
The gas current is simultaneously observed by a suitable meter, which, with subsidiary corrections for pressure, temperature, &c., gives the necessary data for deducing calorific value.
The principles of telegraphy (land, submarine and wireless) and of telephony are discussed in the articles Telegraph and Telephone, and various electrical instruments are treated in separate articles such as Amperemeter; Electrometer; Galvanometer; Voltmeter; Wheatstone'S Bridge; Potentiometer; Meter, Electric; Electrophorus; Leyden Jar; &C.
It was clear, therefore, that in its very nature, house-to-house visitation was both wasteful and insufficient, and it remained for Liverpool to correct the difficulty by the application, in 1873, of the " Differentiating waste water meter," which has since been extensively used for the same purpose in various countries.
In a certain district of 2000 persons, the meter of which records at the time a uniform flow of 2000 gallons an hour, showing the not uncommon rate of leakage of 24 gallons per head per day.
Having arrived at the end of the district he retraces his steps, reopens the whole of the stop-cocks, removes the meter diagram, takes it to the night complaint office, and enters in the " night inspection book " the records he has made.
The ultimate goal, I submit, is not to optimize just meter by meter but what I call "grape by grape," down to each individual piece of flora and fauna.
Forms of open circuit wave meter have been devised by Slaby and by Fleming.
2 In Donitz's wave meter a condenser of variable capacity is associated with inductance coils of various sizes, and the wave meter is placed near the antenna so that its inductance coils have induced currents created in them.
11 a meter or counter is shown associated with the subscriber's line, and in both figs.
The subscriber's meter is joined in multiple with the cut-off relay, and whenever a peg is connected to the circuit a current flows through the meter.
Later apparatus, such as Pettersson's bifilar current-meter or his more recent electric-photographic apparatus, and Nansen and Ekman's propeller current-meter, measure both the direction and the velocity at any moderate depth from an anchored vessel.
This meter is an ampere-hour meter and applicable only to continuous current circu; ts.
Hence the meter is a watt-hour meter and measures electric energy.
A modification of the above meter with some mechanical improvements has been devised by S.
The meter is made up also in a form suitable for use with two or three fixed electric currents.
The resistance of the meter coils causes a fall in voltage down the series coil which reduces the supply pressure to the consumer.
Two points are selected on the surface of the shaft at different positions along it, and the relative displacement which occurs between them round the shaft when power is being transmitted is determined either by electrical means, as in the Denny-Johnson torsion-meter, or optically, as in the Hopkinson-Thring and Bevis-Gibson instruments.
ELECTRIC. METER In the public supply of electric energy for lighting and power it is necessary to provide for the measurement of the electric energy or quantity by devices which are called electric meters.
A third electrolytic meter of the shunted voltameter type is that of A.
In this meter the electrolyte is a solution of mercurous nitrate which is completely enclosed in a glass tube of a particular form, having a mercury anode and a platinum or carbon cathode.
When this is the case, the number of revolutions of the meter in a given time is a measure of the watt-hours or energy which is passed through the meter.
Since the revenue-earning power of a supply station depends entirely upon its meters, inaccuracy in meter record is a serious matter.
The position meter just mentioned is common to all the cords on one position and records all completed calls handled at the position.
Edison, the last-named inventor elaborating a type of meter which he employed in connexion with his system of electric lighting in its early days.
The Edison electric meter, like those of Sprague and Lane-Fox, was based upon the principle that when an electric current flows through an electrolyte, such as sulphate of copper or sulphate of zinc, the electrodes being plates of copper or zinc, metal is dissolved off one plate (the anode) and deposited on the other plate (the cathode).
Hence when a current is passed through the meter, the armature rotates and increases its speed until the driving force is balanced against the retarding force due to the eddy currents in the copper brake disk.
It can be constructed to be either an amperehour meter or a watt-hour meter, but is usually the latter.
In Intermittent Registering Meters some form of ampere-meter or watt-meter registers the current or power passing into the house; and a clock motion electrically driven is made to take readings of the ampere-meter or watt-meter at definite intervals - say, every five minutes - and to add up these readings upon a set of registered dials.
The cost of measuring current by the aid of a meter is made up of three parts: (I) the prime cost of the meter, which varies from £2 to £6 for an ordinary 25-light house electric meter; (2) the capital value of the energy absorbed in it, which if the cost of the energy is taken at 2d.
Per Board-ofTrade unit, with interest and depreciation at 6%, may amount to £10 per customer; and (3) the annual working costs for repairs and also the wages of the staff of meter men, who take the required monthly or quarterly readings.
Meter I z in., weight 44 grains.
Calls are registered by pressing a key, which connects a battery through a position meter of very low resistance to the socket of the line jack, thereby furnishing the necessary energy to the meter.
Some administrations, in addition to employing the ordinary position meter, use a second one for registering ineffective calls.
C. Reed, American Meter Practice (New York, 1904); J.
This current is small, however, and the meter is not operated until a much larger current is passed through it.
Another well-known motor meter, working on a somewhat similar principle, is that of Chamberlain and Hookham.
By the use of a permanent magnet instead of a shunt coil as the bob of one pendulum, the meter can be made up as an ampere-hour meter.
Dean had trouble remembering who was who but all were of like mind in their affection for the old man who turned up the charm meter a notch or two.
In the Long-Schattner electrolytic meter, the insertion of the coin depresses a copper plate or plates into an electrolytic cell containing a solution of sulphate of copper; the passage of the current dissolves the copper off one of the plates, the loss in weight being determined by the quantity of the electricity passed.
The improvements introduced in 1890 and 1891, whereby this state of affairs was put an end to, consisted in the introduction of the principle of supply by meter, and the adoption of a comprehensive system of reducing the initial pressure of the gas, so as to diminish loss by leakage.
A good meter should start with a current which is not more than 2% of its full load current.