The degree of protection of meters against the penetration of water and dust is IP54 according to GOST 14254.
The limits of the permissible relative error of the meters (or the main permissible relative error – for the meters with elements of the correction of temperature readings) are respectively:
– for meters of standard sizes G2,5, G4, G6
– for meters of standard sizes G10, G16
Meters consist of two main nodes located in one building: meter and counting mechanism. The gauge consists of a body and two eight-shaped rotors placed in it, which are mutually perpendicular in relation to each other and rotate in opposite directions. The housing with two spores is closed by walls on which two pairs of bearings are mounted, which are the supports of the rotors. Synchronizing gears are installed on the rotor shafts, which ensure the proper position of one rotor relative to another when they rotate when gas flows.
Meters can be issued with the mechanical or electronic counting device.
In meters with a mechanical counting device, the axis of one of the rotors is connected to the gearbox of the counting mechanism, the gear ratio of which is chosen so that the measured gas volume is measured directly in cubic meters, and in the meters with a magnetic clutch (MF), the rotation from the rotors to the counting mechanism through a magnetic coupling, while the gas in the counting device is absent.
In meters with an electronic reading device: in the wall of the meter, on the side of the reading device, a rotor speed sensor is mounted, which generates a pulse-frequency electrical signal.
The electronic counting device, according to a certain algorithm, processes the frequency-pulse electrical signal and displays the measured gas volume in cubic meters and particles of a cubic meter on a digital indicator board. The counting device has several modes of operation: displaying the value of the measured gas volume in cubic meters, particles of a cubic meter, test modes and other modes depending on the modification.
Meters with an electronic counting device can be telemetry output for remote transmission of information on the growth of the measured gas volume or the current values of the gas meter for use in remote information collection systems.
Meters with a mechanical counting device and a nominal volume flow rate of at least 10 m³ / h can be equipped with a low-frequency pulse generator (such as “potential-free contact”, switched DC voltage not more than 15 V, switched current not more than 120 mA), quantities which is directly proportional to the measured volume of gas flowed through the meters and can be used to work with gas volume correctors.
Meters with a mechanical counting device and a low-frequency pulse generator are explosion-proof and are marked “IExibIIBT4X” (mechanical counting device, magnetic coupling) or “IExibIIBT3X” (mechanical counting device, “gas under glass”) in accordance with GOST R 51330.0-99 ; GOST R 51330.10-99; GOST 12.2.007.0-75 and can be installed in hazardous areas in accordance with the Rules for the Installation of Electrical Installations (Ch. 7.3) and other documents regulating the use of electrical equipment in hazardous areas.
Meters with electronic counting device are marked with explosion protection “0ЕхiаIIАТ4 X” in accordance with GOST R 51330.0-99; GOST R 51330.10-99; GOST 12.2.007.0-75 and can be installed in hazardous areas according to the Rules for the Installation of Electrical Installations (Chapter 7.3) and other documents regulating the use of electrical equipment in hazardous areas.
The electronic counting device has a non-volatile memory for storing the readings of the electronic counting device about the measured volume of gas and the correction coefficients of the meter characteristics. The design of meters with an electronic counting device provides the ability to connect a device to read gas meter readings and correction factors for meter characteristics from a non-volatile memory of an electronic counting device without dismantling the meters, for which the counting device has an appropriate connection space.
The meter does not require direct pipeline sections before and after the meter for its normal operation.