SU426152A1 - DEVICE FOR GRADING AND VERIFICATION OF FLOWMETERS - Google Patents

Description

one

The invention relates to the field of measurement technology and can be used in the calibration and calibration of gas and liquid flow meters.

A device for calibration and calibration of gas flow meters is known, which contains an auxiliary tank, a working gas cylinder, tanks with a liquid, a pressure regulator, start-up and shut-off valves, a liquid flow meter, a rotatable flow meter, and a control system. The scheme is based on the liquid displacing the working gas from the tank at a constant pressure in it.

To simplify the calibration setup scheme, expand the range of operating pressures and temperatures, the proposed device is equipped with a pressure multiplier with an indicator of the position of its rods and with a heat element in a small cylinder that is installed between a calibrable flow meter and an auxiliary tank.

The device contains a pressure multiplier 1, the movement of the rods of which is fixed by the indicator 2. Inside the small cylinder of the multiplier there is a heat element 3, which allows the gas to be heated (cooled) before starting calibration. The container 4 is a reservoir for the gas supplying the large cylinder. The reduction gear 5 allows the required pressure to be set, the value of which is controlled by the pressure gauge 6. The small multiplier cylinder is connected by pipeline through a calibrated flow meter 7 to the start-cut valve 8. Instruments 9 serve to control the pressure and temperature in the small cylinder of the multiplier, and instruments 10 to control the parameters on the flow meter.

The calibration on the device is performed as follows.

The small cylinder of the multiplier is filled with working gas at the required pressure. The heat element 3 is heated (cooled) gas to the operating temperature. Gear 5 opens the gas supply from the tank 4 to the large cylinder of the multiplier and sets the pressure on the pressure gauge 6 to balance the working pressure of the gas in the small cylinder and overcome the frictional forces during the movement of the multiplier rod. Include

valve 8, and the gas from the small cylinder of the multiplier expires through the graduated flow meter 7.

The displacement of the multiplier rod ensures that the pressure in the small cylinder is constant during calibration. The expansion of the gas in the small cylinder does not occur, since its outgoing volume is compensated by the movement of the rod and, therefore, the gas temperature does not change. Expiration occurs in

for some time Dg,

then the valve 8 is closed and the distance D5 is fixed by the indicator 2 for changing the position of the rod, and the distance moved by the rod during time A. Gas consumption is calculated by the formula

ABOUT -

ZRTo t

where RO is the pressure of the working gas;

TO is the temperature of the working gas;

R is gas constant;

Z-gas compressibility factor;

F is the stock section area. The accuracy of the calibration with the aid of a device is determined by the class of instruments by which the quantities in the formula are measured.

Subject invention

A device for calibration and calibration of flow meters, which contains an auxiliary tank, a reducer, a shutoff start valve, parameter monitoring devices and a rotatable flow meter, characterized in that, in order to simplify the calibration setup and expand the range of operating pressures and temperatures, it is equipped with a pressure multiplier an indicator of the position of its rods and with a heat element in the small cylinder, which is installed between the meter to be tested and the auxiliary tank.

2SG