Water Meters

The water meter is a measuring device designed to measure the volume of water flowing through closed pipes, at a pressure higher than the pressure of the surroundings and working at back pressure on the outflow side. The unit of measurement used in water meters is cubic meter (m³).

Each water meter consists of: a counting mechanism, a set of rings and a body. A detailed description can be found here >>

As of October 30, 2006, Directive 2004/22/EC of the European Parliament and of the Council of Europe of March 31, 2004 concerning measuring instruments came into force. The directive covers 10 categories of measuring instruments, including water meters. The directive is colloquially known as 'MID' from the first letters of its English name - Measuring Instruments Directive. MID implements a conformity assessment system replacing the previously existing system of legal metrological control for type approval and primary legalization. The MID Directive has fully replaced the GUM regulation.

The continuation of the MID Directive 2004/22/EC is Directive 2014/32/EU of the European Parliament and of the Council of 26 February 2014 on the harmonization of the laws of the Member States relating to the making available on the market of measuring instruments. This directive specifies the requirements that measuring instruments must meet when they are made available on the market or put into service for the performance of measuring tasks.

Changes in flow designation:

• Q₁ (previously Q_min) - minimum flow rate - the smallest flow rate at which the water meter readings meet the requirements for permissible limit errors.
• Q₂ (previously Q_t ) - intermediate flow rate - is the flow rate value occurring between the continuous and minimum flow rate, at which the measuring load range is divided into two upper and lower intervals. Each interval has a characteristic limiting permissible error.
• Q₃ (formerly Q_p, formerly Q_n )- continuous flow rate - the highest flow rate at which the water meter operates properly under normal operating conditions, i.e. under continuous or intermittent flow conditions.
• Q₄ (formerly Q_s )- overestimated

Summary of water meters by flow rate
Dimensioning of water meters from GUM to MID - with both maintaining the same metrological range from Q₁ to Q₄:

When selecting a water meter, the most important information is to determine the flow rate, type, expected R coefficient, temperature class, location and any other requirements (including the method of remote communication) set by the user.

Temperature class (in device designation preceded by the letter "T") minimum and maximum permissible water temperature that the water meter should withstand continuously for a specific internal pressure, without deterioration of its metrological characteristics.

This is the range of measuring loads of the water meter, for which the water meter readings are within the limits of acceptable margin errors.

This is the class of the water meter indicating the maximum pressure loss in continuous operation flow rate, caused by the presence of a water meter in the pipeline, expressed in kPa, preceded by the letters "ΔP" in the markings.

In order to prevent damage to the water meter due to low temperatures, the water meter should be operated at an ambient temperature of 5-55°C, the minimum temperature of the measured water is 0.1°C.
The range of water temperatures, depending on the temperature class of the water meter, can be divided for cold water into:
a) T30 - from 0.1°C to 30°C
b) T50 - from 30°C to 50°C,
or for hot/hot water meter:
a) T90 - from 0.1°C to 90°C,
b) T130 – from 0.1°C to 130°C,
c) T30/130 from 30°C to 130°C;
When selecting a water meter, special attention should be paid to the temperature at which the water meter will operate. If the water meter is used contrary to its intended purpose, it may be damaged.

Pursuant to the Regulation of the Minister of Economy of 23 October 2007 on the requirements to be met by water meters and the detailed scope of checks performed during the legal metrological control of these measuring instruments, the water meter should be permanently and legibly placed, separately or in one place the following designations:

• manufacturer's name or mark;
• conformity marking, within the meaning of article 5 point 3 Act of August 30, 2002 on the conformity assessment system (Journal of Laws of 2004, No. 204, item 2087, as amended 4), additional metrological marking and the number of the notified body;
• Factory mark;
• Production year;
• Serial number;
• One or two arrows indicating flow direction;
• Unit of measure "m³";
• The maximum allowable pressure, if different from 1 MPa (10 bar);
• If the water meter can only work in a vertical position - the letter "V", and if in a horizontal position - "H";
• Numerical value of continuous flow rate;
• Q3/Q1 ratio, preceded by the letter "R";
• Q2/Q1 ratio if different from 1.6;
• Temperature class, if different from T30;
• Pressure loss class if different from ΔP 63;
• Output signal to auxiliary devices, if any;
• The number of the EC type examination certificate or the EC design examination certificate referred to in the regulations of the act of August 30, 2002 on the conformity assessment system.

Reading can be made by visual-manual reading of indications from the water meter dial, or by means of remote reading modules.

Placing an arrow on the body of the water meter clearly informs about the required direction of flow, for which indication errors were checked during the conformity assessment. Installation inconsistent with the indication of the direction of flow does not result in damage to the water meter, however, the indications of the water meter may be different than the indications of the water meter installed in accordance with the direction indicated by the arrow on the body.

In accordance with the Announcement of the Marshal of the Sejm of the Republic of Poland of June 7, 2016 on the Act - Law on Measurements, Journal of Laws 2016 item 884 and the Regulation of the Minister of Entrepreneurship and Technology of March 22, 2019 on the legal metrological control of measuring instruments, Journal Of Laws item 759, it is stated that the measuring instrument should be submitted for re-verification before the expiry date (specified in the regulations issued on the basis of Article 9 point 4) of the validity period from the conformity assessment. For water meters, this period is 5 years. In sec. 2 point 2, it is stated that the period of legalization is counted from the first day of December of the year whose marking was applied to the instrument during the conformity assessment and ends on November 30 of the fifth year. Information about the year in which the conformity assessment was carried out is included in the metrological marking on the measuring instrument (capital letter "M" and the last two digits of the year).

In accordance with the Regulation of the Minister of Entrepreneurship and Technology of March 22, 2019 on the legal metrological control of measuring instruments, Journal Of Laws item 759 - the date of application for re-verification of the water meter that has been secondarily verified (legal metrological control) is determined by means of a monthly mark with a Roman numeral meaning the month of completion/expiration of the verification and an annual mark with symmetrically placed Arabic numerals meaning the last two digits of the year of validity. If the verification expires, the water meter cannot be the basis for settlements.

The minimum allowable pressure (mAP) on the downstream side at the outlet from the water meter should be 30 kPa (0.3 bar).

It is a parameter defining the metrological (measurement) range of the water meter. It is expressed as the ratio of the continuous flow rate Q3 (continuous flow rate - the highest flow at which the water meter works properly under normal conditions of use) to the minimum flow rate Q1 (minimum flow rate - the flow rate at which the indications are within the limits of acceptable metrological errors). Thus, the higher the value of the R coefficient, the greater the range of the water meter measures the volume of flowing water. As it follows from the above, increasing the R factor can be done by increasing Q3 or by decreasing Q1. The lower the Q1, the greater the sensitivity of the water meter.

The installation location should provide easy access for the process of installation, removal, servicing, and reading, and be separated from rooms in use or for storage. Protected from adverse weather conditions and protected from the effects of electrical and gas installations. Valves shall be provided upstream and downstream of the water meter in order to shut off the water supply if necessary to replace or remove for inspection or repair, with the possibility of completely uncovering the cross-section of the supply pipe The accuracy of the water meter indications may be affected by flow disturbances occurring before or (to a lesser extent) after the water meter, caused in particular by the presence of fittings disturbing the flow, e.g. elbows, valves, filters, pumps, etc. It is recommended that the water supply system be equipped with straight sections of the pipeline upstream and downstream of the water meter of appropriate length, so as to minimize the impact of flow disturbances on the measurement carried out by the water meter.

The degree of protection (IP) is a numerical measure according to EN 60529:2003. The IP protection degree is a parameter characterizing the housing of the device, informing about what protection the housing provides against ingress of foreign solids and ingress of water. The degree of protection of the water meter counter determines the possibility of using a given type and design of the water meter for specific environmental conditions. Fogged up "glass" of the water meter may indicate that the device is not properly selected for the environmental conditions in which it works.

A water meter with external signs of damage and/or a broken seal should be immediately reported to the administrator for appropriate steps to be taken. In the case of a damaged water meter or a damaged seal, first inform and agree on the terms of replacement with the caretaker. Then you should decide on one of the options – repair the water meter or buy a new water meter. In the case of the first option, the water meter should be dismantled and replaced with a water meter, straight pipe or other fittings element, and then the damaged water meter should be sent to a unit dealing with repair and secondary verification. After secondary verification, the water meter should be installed, and the connection from the supply side should be protected against unauthorized access according to the administrator's guidelines. In the case of the second option, a new water meter should be installed, securing the connection from the supply side as described above. and the replaced water meter should be recycled.

All water meters manufactured by Apator Powogaz in the basic version are adapted for remote readings by means of communication overlays. Special versions NK or NKOP are adapted to work with reed switch transmitters (NK) or with optoelectronic transmitters (NO).

Yes. Wireless and wired remote reading is not harmful to health. This is confirmed by declarations of conformity issued for radio communication modules, issued by the Manufacturer, based on specific European Directives and harmonized standards.

The basic legal act is DIRECTIVE 2014/32/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of February 26, 2014 on the harmonization of the laws of the Member States relating to the making available on the market of measuring instruments. In Art. Article 1 of this Directive lays down the requirements that measuring instruments must comply with when making them available on the market or putting into service to perform measurement tasks… The following harmonized standards apply with the Directive: EN 14154-1;-2;-3:2005+A2:2011; EN ISO 4064-1;-5:2014; OIML R 49-1; WELMEC Guilde 11.1; 3.