A question from construction of psychrometric chart

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SUMMARY

The discussion centers on the placement of a wet-bulb temperature of 69 degrees Celsius on a psychrometric chart and its relationship to the saturation line at 100% relative humidity. Participants clarify that the wet-bulb temperature is plotted vertically above the corresponding dry-bulb temperature on the horizontal axis. They emphasize that at 100% humidity, the wet-bulb and dry-bulb temperatures are equal, and any deviation indicates wet-bulb depression due to moisture evaporation cooling the bulb.

PREREQUISITES
  • Understanding of psychrometric charts
  • Knowledge of wet-bulb and dry-bulb temperature concepts
  • Familiarity with relative humidity measurements
  • Basic principles of thermodynamics related to moisture evaporation
NEXT STEPS
  • Study the construction and interpretation of psychrometric charts
  • Learn about the principles of wet-bulb depression
  • Research the effects of humidity on temperature measurements
  • Explore tools for calculating psychrometric properties, such as the ASHRAE Psychrometric Chart
USEFUL FOR

This discussion is beneficial for HVAC engineers, meteorologists, and anyone involved in environmental control systems who needs to understand the relationships between temperature, humidity, and psychrometric properties.

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There is wet-bulb temperature of 69 centigrade in the picture which I cannot understand how it is placed there and what is the relation between it and saturation line (RH of % 100)

Thank you
 

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There's some sort of problem with the attachment.
 
The diagonal lines are constant wet bulb: so that's the label of the line it is next to.
 
this the second related picture
 

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mech-eng said:
There is wet-bulb temperature of 69 centigrade in the picture which I cannot understand how it is placed there and what is the relation between it and saturation line (RH of % 100)
Isn't it 69 degF not C ?

It'd be placed vertically above the 69 on horizontal axis
because
at 100% humidity , wet bulb and dry bulb are the same ? And at any other humidity there's wet bulb depression ?

Remember what's going on on that psychrometer - moisture is evaporating, cooling the bulb. They're plotting that depression.
 

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