GOST 12.3.018-79

Random Section of GOST 12.3.018-79

3.2.       Ventilation systems and components thereof shall be inspected, and identified deficiences shall be eliminated.

3.3.       Indicating instruments (differential pressure gauges, psychrometers, barometers, etc.), as well as related communication lines, shall be located so as to minimise any impact of airflow, vibration, convection and radiation heat that might influence their readings.

3.4.       Instruments shall be prepared for testing in accordance with resrective specifications and current guidelines for their operation.


4.1.      Tests shall be carried out at least 15 minutes after the ventilation unit is started up.

4.2.      The following shall be measured during testing depending on the program:

the barometric ambient pressure, Ва, in kPA (kg force/m2);

the temperature of the transported air by a dry and wet bulb thermometer, t and fj, °С, accordingly;

the ambient air temperature within the operating area of the room, ta, °С;

the dynamic pressure of the air flow at the gauge cross section location, рdi, kPA (kg force/m2);

the static air pressure at the gauge cross section location,рsi, kPA (kg force/m2);

the full air pressure at the gauge cross section location,рi, kPA (kg force/m2);

the time of the wind gauge trip within the area of the gauge cross section, t, seconds;

the number of graduations of the mechanical anemometer revolution counter mechanism during the time period (t) of the cross section enclosing (п).


1.      Static pressure or full pressure shall be measured by defining the pressure produced by the fan and pressure losses in the ventilation system or at its section.

2.      Values of full pressure (р, kPa, kg – force / m2) and static pressure (рs, kPa, kg – force / m2) represent appropriate drops of full pressure and static pressure of the flow against barometric ambient pressure.  A drop is considered positive if the related value exceeds the ambient pressure, otherwise р and рs are negative.

4.3.       In cases, when air flow pressure and speed are measured in air ducts, and the gauge cross section is located at a straight section, with a length of at least 8Dh, a combination pressure receiver may be applied to measure static pressure of the air flow and full pressure at separate points of the cross section.

4.4.       Clearances between instruments and openings through which they are inserted into enclosed conduits shall be sealed for the period of testing, and openings shall be closed after the test is completed.


5.1.       The following shall be estimated on the basis of values measured in accordance with the testing program:

relative humidity of transported air, j, %;

density of transported air, р, kg / m3 (kg force·sec2/m4);

air flow speed, v, m / sec;

air flow rate, L, m3 / sec;

losses of full pressure in the ventilation system or its separate components, Dр, kPa (kg force / m2);

factor of pressure losses in the ventilation system or its component, z.

5.2.       The relative humidity of transported air shall be assessed on the basis of wet and dry bulb thermometer readings in accordance with the instrument certificate (specifications).