Vern did say he wants to forge 1084, that's why I went with that temp range.
I use the last 3 or 4 heats to do any final straightening and touch ups as well as lowering the temps to normalize at the same time; the last 2 heats there shouldn't be any hammering taking place to not induce any more stresses.
You should be able to get a PID and K type thermocouple for about $50.00 shipped, maybe less. Use the PID as a temp guage, they're cheaper than a pyrometer.