HDT test - deflection v. time curves

Does anybody know if it is possible to find somewhere deflection vs time (i.e. temperature) curves recorded during HDT tests?

Do you know if actually the test apparatus to conduct such tests (and VICAT tests as well) usually allows to record such data instead of just the time/temperature at which the displacement reaches the ISO / ASTM specified limit?

My question arises from the fact that the change of deflection in time (and in temperature as well) might not be a straight line, and that would mean that a change in the conventional maximum deflection would strongly affect the comparison between different materials based on HDT values.

Thanks for any help

Sergio