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Secondary standard for dew point

Secondary standard for dew point

The VYMPEL-ED 300 secondary national standard is designed to reproduce a given dew (frost) point value and hydrocarbon condensation temperature in a synthetically generated gas mixture. This data can then be transferred to lower level reference hygrometers and operational measuring devices, and used for R&D in the field of metrological support of hygrometry.
All SPA Vympel instruments are calibrated using the VYMPEL-ED 300 secondary standard for dew point and hydrocarbon condensation temperature.
This standard is traceable to the Russian National State Primary Standard for gas relative humidity and is the only secondary standard in Russia reproducing water and hydrocarbon condensation temperatures under pressures up to 30 MPa. The ED-300 standard also allows for testing under realistic conditions thanks to its ability to simultaneously reproduce a water dew point temperature and hydrocarbon condensation temperature at the operating pressures.
The Vympel-ED 300 consists of two independent modules: the first module reproduces the water dew point, the second module reproduces the hydrocarbon condensation temperature.
As a result, the water dew point (DP) and hydrocarbon condensation temperature (HCT) can be reproduced at the same time. Depending on what DP / HCT combination is required, the gas is either passed first through the DP generating module and than through the HCT saturating module or vice versa.

Signature features:

Water dew point and hydrocarbon condensation temperature reproduction under pressures up to 30 MPa
The phase equilibrium method of standard thermal static units is used to generate dew point/condensation temperatures for water and hydrocarbons, respectively
The water dew point and hydrocarbon condensation temperature are reproduced at the same time

Characteristics

Dew/frost point temperature range
-80...+30°С
Hydrocarbon condensation temperature range
-50...+30°С
Operational pressure range
0,001...30 MPa
Output gas flow limit
5 l/min
Upon temperature reproduction:
Temperature range:
Dew/frost point temperature
-60...+30°С
Dew/frost point temperature
-80...+30°С
Hydrocarbon condensation temperature
-50...+30°С
Upon temperature reproduction:
Absolute error limits
Dew/frost point temperature
±0,09°С
Dew/frost point temperature
±0,14°С
Hydrocarbon condensation temperature
±0,25°С
show all Characteristics

Principles of operation:

The phase equilibrium method of standard thermal static units is used to generate dew point/condensation temperatures for water and hydrocarbons, respectively.
The Vympel-ED 300 consists of two independent modules: the first module reproduces the water dew point, the second module reproduces the hydrocarbon condensation temperature.
As a result, the water dew point (DP) and hydrocarbon condensation temperature (HCT) can be reproduced at the same time. Depending on what DP / HCT combination is required, the gas is either passed first through the DP generating module and than through the HCT saturating module or vice versa.
Each module consists of one saturator and from one to three separators.

Saturator

The saturator serves to saturate the gas with water or hydrocarbon vapors. It is immersed in liquid bath where a specific temperature is maintained thermostatically. In the DP generating module the temperature is positive, whereas in the HCT generating module it can be either positive or negative.
The saturator is a tightly sealed metal vessel with the following components: pos. 6: a flow diffuser consisting of a quartz sand layer between layers of metal mesh; pos.5: an aerosol filter consisting of 2 layers of metal mesh with a cotton layer in between; pos.1: deflector.
There are also 3 tubes: pos. 7: gas inlet; pos. 2: gas outlet; pos. 4: distilled water or hydrocarbon inlet.
The gas saturation process is as follows: gas is supplied to the saturator inlet and passes through the flow diffuser, where the gas stream is broken up into small jets that enter the liquid creating small bubbles. These bubbles pass through the water/hydrocarbon layer, where the gas becomes saturated. Next, it passes through the aerosol filter, where any aerosols are removed from the gas flow. Then, the deflector interrupts the direct flow of any aerosols remaining after the filter, and the gas enters the outlet via the hole, pos. 3.

Separator

The separator is designed to remove excess moisture or hydrocarbons from the gas. Like the saturator, it is submersed in a liquid where the temperature is maintained by means of a thermostat. The separator has two or three stages. These consist of interconnected serpentine chambers encased in an airtight metal body. The gas is supplied to the inlet, pos.1, and then passes through all of the separator stages. During this process all of the excess liquids in the gas (moisture or hydrocarbons) collect on the inner walls of the chambers. Subsequently, the gas leaves the separator via the outlet, pos. 2. As a result of this process, the gas gains a dew point/hydrocarbon condensation temperature equal to the thermostatically controlled temperature.

VET-158-1-2004 Standard

Secondary standard of a dew point