I don't know the actual use of the "CURRENT LOOP" interface.
All I can say is that you refer to page 3-9 of the manual. But note well that, if experimenting with applying "external load configurations" you need to heed the warning about the requirement for a load resistance of "adequate power rating".
Lastly, don't forget two aspects that often get overlooked:-
1) The oscilloscope output. I always liked to check-out the various waveforms.
2) "Crest factor" (CF) - both 454A and QA-ES display these values.
Basically, CF= Peak Volts/RMS Volts. It is desirable to have a high CF when Coagulating tissue and a low CF when Cutting tissue. CF is an indication of how well an ESU output can Coagulate without Cutting. Typical values are around 1.4 for pure sine wave to about 10 for Coag.
Crest Factor is defined as a ESU's ability to Coagulate without Cutting. The ideal is to slowly shrink the top layer of tissue whereby the capillaries seal off bleeding without causing any further penetration or tissue necrosis. In order to achieve this ideal, the CF for Coag must be as high as possible - typically rated as a multiple of RMS (
eg, CF of 7 to 10). If CF is high enough, the power under load will ideally drop to zero before cutting. This is also proof of a High Impedance source.
By the way, I've never used a 454A myself. The best I ever had to make do with was the Bio-Tek RF-302 (and before that, various "home made" options of the "needs must" variety).
