How to read the pseudoreduced gas compressibility chart?

[Pcordovabaya]

Hello, I need help with this graphic:

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I don't know how to read it, I have a Pr of 3.2 and a Tr of 1,5.
Can someone tell me the scale of this graphic?

The graphic is here too:

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Thanks

EDIT:
LOL!!!! it was really easy, I think the time is affecting me 12:11 am here.

Here it is:

[link Point to another website Only the registered members can access]

[mhabulletin]

This graph is used in the same way as the Katz-Compressibility chart where you can read the Z gas factor. Here it is. On the Pr axis locate your value of 3.2 that is roughly in between the 3 line and the next immediate line (that is 3.5) and mark it the same with your digital pen. Now on the Tr scale find the 1.5 value curved line that is going up on the chart. Extend a line from 3.2 and moving along the 1.5 and where both intersects is the value of the Pr,Tr and project this point to the left axis (Y axis) and read the Cr value there that by my reading should be around 0.25 and that is your pseudoreduced gas compressibility value.

I hope it helped!
Mha

[mhabulletin]

This graph is used in the same way as the Katz-Compressibility chart where you can read the Z gas factor. Here it is. On the Pr axis locate your value of 3.2 that is roughly in between the 3 line and the next immediate line (that is 3.5) and mark it the same with your digital pen. Now on the Tr scale find the 1.5 value curved line that is going up on the chart. Extend a line from 3.2 and moving along the 1.5 and where both intersects is the value of the Pr,Tr and project this point to the left axis (Y axis) and read the Cr value there that by my reading should be around 0.25 and that is your pseudoreduced gas compressibility value.

I hope it helped!
Mha