Dew point issue
Thread Content
Is the dew point requirement for instrument air -40 degrees at atmospheric pressure, or -40 degrees at 0.6 MPa?
Requirements for instrument air: 3.0.2 The dew point of the instrument air supply at operating (online) pressure shall be at least 10°C lower than the lowest extreme temperature recorded in the corresponding year (season) in the location where it is used. Last edited by Pseudo Xiaobao on 2009-2-25 20:57.]
The dew point temperature corresponds to a certain level of moisture content. In other words, when the instrument gas contains X g/m^3 (mg/L) of water, and all of this water precipitates at a temperature of Y degrees Celsius, then Y is the dew point temperature. Therefore, the dew point temperature of the instrument air is the temperature at which the average lowest temperature occurs; the moisture content required in such conditions must be less than the water content at that temperature, X! This post was last edited by Nine Heavens is me on 2009-2-25 21:17]
This dew point should be at 0.6 MPa；
In laboratory analysis, the weighing method is used, and the result is also adjusted to standard pressure, corresponding to 0.6 megapascals as shown in the curve graph.
For instrument air, the dew point is required to be at -40 degrees at a pressure of 0.4~0.6 MPa