Water meter

The measurement of the consumed water flows is an old problem, that it is for an agricultural use (Irrigation), industrialist or domestic. The example of the table of Frontin watch which the technician for a long time sought to evaluate in an objective way consumed volumes of water because this evaluation is useful for several reasons: dimensioning of the equipment, controls water losses, distribution of the production costs, etc A Compteur is based on the principle which one cannot measure precisely the quantity of water passed in a drain: it is thus about an estimate of the real flow. The only reliable method would be to measure the Volume filled out in a container in a definite time.

Water meter

The cost of water treatment is very important. The monitoring and the exact calculation of consumption become a requirement of the consumers (pollutant/payer). The installation of individual water meters (residences, industries and trade, communities, etc) is inescapable. The legislator opened the possibility, with the joint owners of a building, to vote, in the majority absolute of the voices (article 25/1) then in the majority simple, the installation of individual meters.

History

The equipment of the past

The first domestic meters are installed in Paris in 1876. (source). It are manufactured by… Models most usually installed:

Principal manufacturers:

Many other models of meters were invented and subjected to the communities. For example:

The meter LAMBERT ¹ - Meter JACQUET ¹ - Meter HIRT ¹ - Meter PIOZ ¹ - Meter PAYTON ¹ - the meter Frager (1883)

Current meters

Manufacturers

Sensus Metering Systems is first world. The numbers two and three are Actaris and Elster. Other competitors are: Sappel, CDC, Tagus…

Foreseeable evolution

Types of water meter and operating process

This measuring instrument is subjected to the control of the State by. Any meter comprises a serial number, numerical or alpha-numeric, engraved in material of the carcass, on the dial or the protective mobile shutter of the window of the index. It is often provided with a seal, placed on connection upstream, to prevent any attempt at fraudulent use.

General features

A meter is posed at the beginning of the network which one wants to supervise consumption. A shut-off valve (gate valve) makes it possible to cut off its supply in order to facilitate its disassembling. It is recommended to place this tap near the meter.

principal arrival - > valve - > sealed - > meter - > district distributers - > taps

The installations are sometimes equipped with a pressure regulator placed after the water meter because a high pressure can damage the network. A water meter functions only in the beach of Pression S for which it was conceived. It is equipped with a dry or drowned dial. The drainage duct makes turn a rotor to wings or an eccentric piston. A system of gears with exhaust involves displacement by successive pawls of an arrow or a toothed wheel. In decimal system, each time a toothed wheel carried out ten steps, it advances the following wheel of a step.

A standard meter can indicate consumption until the decilitre (4 red digits) but the use retains only one invoicing with m3 (black figures). See the dial of a meter Schlumberger

Speedometer

Function like the water mills. It is not very sensitive to the impurities contained in water. Likely not to detect the light escapes. Horizontal installation.

Volumeter

It contains a hollow roll, which rocks to feed the cicuit. Sensitive to the impurities contained in water. Record the low flows.

Heating meter

Calculation associating the flow AND its temperature.

Other meters

Other shapes of counting of the water requiring of the measuring instruments

Log (boat): tool intended to calculate the rate of travel.

Courantomètre: a propeller plunged in water (river, drain, channel) is driven by the displacement of water. The number of rotations determines the current velocity. The volume of flow can thus be estimated by integrating the section of the conduit in the formula of computation.

Kinds of water meters

The water meters line up in two categories: principal meters and check meters . For specific needs, the construction of a building, a building site of restoration of the facade, it is made use of temporary meters called meters of building site , posed by the Service of water concerned.

The main thing

The principal meter of an installation is generally that to which is connected the water arrival intended to serve the site (a building, a property, an industrial building, an agricultural land. This meter which usually belongs to the Distributive firm is placed under the monitoring of the subscriber. Its installation is subordinated to the concluding of a supply agreement between the Concessionary company and the customer (the subscriber). According to the nature of the activities served by this meter, the regulation requires the installation of a Disconnecteur. The regulation requires the installation of safety device, disconnecting type, non-return valve (decree 89-3)

Divisional

One calls check meter or under-meter a meter located downstream from an other meter, generally called principal meter . This installation is intended to calculate the consumption of a particular installation:

- various residences of a building. It is the most frequent case.

- activities of a site, by nature (production, watering, cleaning, etc)

Maintenance

A water meter is put out of order with the age. The reasons for this degradation are multiple: wear, residues of limestone, acidity of the liquid. This disordered state is always done for the benefit of the customer. Indeed, the meter underestimates.

It must be protected from the effects of freezing.

Statement of consumption

The index of the principal meter is raised by the agents of the Distributive firm.

The management of the check meters can be the subcontract object which can include until the transfer of property of the meters.

Manual statement

Visual monitoring of the indices.

Radio-raise

The meter is equipped with a system of contact whose end is off-set by wire towards a place easily accessible by an elevating agent (it is a telerepetitor). The radio operator statement is carried out thanks to a transmitting téte clipsée on the meter which sends the data of consumption (emitted by radio waves) to a receiving device " antenna radio" that the raising device moves according to the rate of reception. The most complex systems envisage a remote consultation by telephone link (telegraphic or radio): it is tele changing.

Invoicing (in France)

The dealer adapts the periodicity of the invoicing according to consumed volume. An invoice is emitted consecutively with the visit of the elevating agent. In the event of impossibility of access to the meter, it will be established on an estimate of consumption.

Components of a water invoice

The components of an invoice are very many and variable according to the local government agencies. They are collected by the dealer. One finds mainly:

the access to the service (subscription intended for the dealer),

and those, whose cost is proportional to consumed volume:

the distribution (pumping, use of the networks and the works),
purification and the Treatment of the waste water,
taxes collected on behalf of the public agencies and trade unions:

Fight against pollution,
inland Waterways of France,
Agency of water and safeguarding of the resources,
Financing of the utility services,

Totality is subjugated with the VAT.

Methods of the distribution of the cost of the water consumption in apartment building equipped with meters

At the conclusion of the period of the deferred charges, it is made a statement of the indices of the check meters. The comparison with the statement of the period n-1 makes it possible to make the m ³ deducted by each meter. In parallel, the received invoices of the dealer get, for the period considered, at the same time, the total of the supply (many m ³ raised to the principal meter) and the amount of the expenditure, One from of deduced the average costs from the m ³ of water. According to the dates on which the various readings are taken, a discordance can appear between delivered volume and that consumed. So that the calculation is perfect, it is advisable, for each period, to note in same time, the indices of all the meters (the main thing and divisional), It is necessary, also, that the consumption intended for the equipment commun runs (household, watering, boiler room, etc.) that is to say also served by meter. If there is persistence of a significant and repeated variation, it is advisable to make appraise the installation to detect leakages in the network or of the faulty meters. Method 1 - the price of the m ³ is affected with the volume calculated by each meter and charged to its user. It thus pays the real price invoiced with the community. The variations, in more or less, are regarded as being used by the service of the commun runs. This variation, in any event, is corrected in fact during the following exercise.

Method 2 - individual volumes are transformed into relative volumes (expressed as a percentage) and the invoices are distributed according to this percentage. There is no variation but the average costs of the m ³ do not reflect reality. Method 3 - direct Subscription. Each batch is served directly by the Concessionary company which, in this case, addresses an invoice to its subscribed customer. The commun runs have an individual meter whose expenses are distributed with the percentages of joint ownership. The payment of joint ownership can envisage other forms of distribution.

It will be noted that the share of the cost of the subscription of the principal meter, can be distributed according to the number of meters. That has, for effect, to reduce the note of the large-scale consumers. But one can as admit as, those, consuming more, they contribute to the acceleration of the ageing of the equipment. ----

References

Notes

1 - Documents of the national Academy of arts and trades, numerical Academy.

Bibliography

Other sources

external Bonds
- Numerical Academy of arts and trades - CNUM
- ParisTech - Publications of theses - Thesis of A. PASANIS

Other technical documents

Catalog

Some photographs of meters

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