Yes; it's encouraging that the outputs are so similar.
If I remember rightly, the pulp tester is basically a big nerve stimulator (a bit like TENS) ... that's "big" in terms of pulse amplitude (voltage).
There should be a patient response push-button; so you shouild check that out as well.
If I were you I would sketch (or photo) outputs at various settings to be able to compare when you check "next time" (PM, or whatever).
Have you been able to check that the user has been happy with performance? ... "tingling" sensation by the patient?
I was wondering why Wang
et al chose a 2 Meg load ... I would like to see what results would be with (our old friend) 1 K. But then I found this in a Users Manual for another tester (so it's yet another case of Ohm's Law):-
The tooth enamel of a patient is simulated using a 2 Meg-Ohm resistive load. Using this load as a reference, the absolute maximum voltage that can appear at the electrode is 500 V at a maximum output current of 250 uA.
Extract from the Digitest Users Manual:-
Max AC Component Amplitude:- 500 V peak-to-peak
Peak Output Current Maximum:- 250 uA
Pulse Durations (Packet Width):-
High (3 bars): 60.5 ms
Medium (2 bars): 100 ms
Low (1 bar): 124 ms