Relative humidity value by a temperature thermocouple

Hello,
Has anyone developed the relative humidity value by a temperature thermocouple?
I also have pressure values. I have seen some formulas to get the humidity value by temperature value, but is complex.

For any usable humidity value, you need wet bulb and dry bulb temperatures. Why bother?

A decent generic Relative Humidity / Temperature transmitter can be had for about $150 US. I'd just do that.

Yes, I know that. There is already the thermocouple in place. And we are in a critical situation of 180°C and 6 bar pressure. I have the formulas to work with wet bulb and dry bulb temperatures. Just wanted to see if there was something easier. Thank's.