it's "take-off thrust set" and then watch engine parameters for anomalies and trust your calculation.
engines not producing takeoff thrust should be shown by the EPR gauge
(
https://en.wikipedia.org/wiki/Engine_pressure_ratio ; for modern airliners)
fan rpm is also a good indicator of thrust as you generally notice when a blade is missing
i suppose with modern computers you could introduce monitoring of horizontal acceleration but it seems like it's mostly worked until now