Regarding the dew point meter
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This post was last edited by zxhong811029 on 2017-5-10 14:49. We have a set of equipment for measuring the dew point of natural gas, with a requirement of below 1 ppm. We found that during the hot summer days, the difference from the normal dew point is quite large. Is the dew point value measured at this time the actual value (theoretically, without considering the quality of the probe)? If not, is it necessary to use a formula to convert it into a value at normal temperatures? Also, is the dew point temperature chart we usually see based on measurements taken at an ambient temperature of 20 degrees? My QQ number is 45072631; I live in Nanba Town (ask for verification via QQ). I am extremely grateful that everyone is willing to help me.
Help push! I only have a vague understanding; I need to imagine it!
If the difference is not significant, it’s considered normal. The cold mirror dew point meter used in our set of standard gas testing equipment shows a minimum difference in dew points between summer and winter of around 10 degrees. Which brand of dew point meter are you using? Dew point meters that use the capacitance method are affected to some extent by temperature, but they generally come with temperature compensation.
Theoretically, temperature has little effect on the water dew point. In the summer, the dew point temperature in the humidity calibration system rises due to high humidity in the air. For example, the humidity calibration system can reach -85 in winter, and -75 in summer. This has nothing to do with dew point meter measurements. Theoretically, as long as the dew point is lower than the temperature of the gas itself, it doesn’t matter whether it’s 20 degrees, 30 degrees, or 0 degrees. In practical applications, the reason why the water dew point for natural gas is required to be 5 degrees lower than the gas temperature is that, although the dew point is lower than the gas temperature, condensation still occurs occasionally. Especially when the difference is within 2 degrees, there are relatively more of them. Putting aside the issue of the instrument’s own precision, I think the cause lies in the dehydration device.