That is
compressor inlet temp, GR. And indeed the Tmo was 127°C, on the nose. After compression of 82:1 (from both the intake ram/shock and the spinning compressors themselves) the
Turbine Inlet/Entry Temp was much higher.
I found the following from another
Flight Global article on the development of the Olympus 593 from 1969 (Author: M. H. Beanland, Asst. Chief Development Engineer, Olympus 593, Rolls-Royce Bristol Engine Division):
https://www.flightglobal.com/FlightP...20-%201603.PDF
"The need for this** can be appreciated when it is realised that the temperature of the air leaving the compressors at cruise, and before any fuel has been burnt in it, exceeds 600°C; and that although the cruise turbine-entry temperature is substantially lower than that at take-off, the actual turbine-blade metal temperature is higher at cruise than at take-off, due to the much higher cooling-air temperature."
** "this" was an intake heater to simulate supersonic cruise conditions when testing the 593 on a Vulcan at subsonic speeds