A question from construction of psychrometric chart

[mech-eng]

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

 

[SteamKing]

There's some sort of problem with the attachment.

 

[russ_watters]

The diagonal lines are constant wet bulb: so that's the label of the line it is next to.

 

[mech-eng]

this the second related picture

 

[jim hardy]

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.