The T-ROESY block is an improved variant of the conventional ROESY block that consists of train of hard 180º pulses alternated in phase. The advantage over the NOESY block is that Overhauser enhancement is always positive, never approaching zero.

Easy implementation on AVANCE spectrometers.

 See  2D ROESY and related experiments.

The standard way to implement a T-ROESY block is:

... d12 pl27 4 p12 ph2 p12 ph3 lo to 4 times l4 ...

in which:

• p12 is the 180 pulse (in usec) from the f1 channel applied at a power level pl27.
• d12 is the minimum delay (20 msec) to set pl27.
• l4 defines the overall duration of the loop or ROESY mixing time.
• The phases ph2 (set to 0) and ph3 (set to 2) may be specified at the end of pulse program.

 See  2D ROESY and related experiments.