Electrosurgical generators that depend on spark-gap circuitry show great variations between individual machines at similar dial settings. This can be of importance in operating suites where one does not always use the same generator. Moreover, spark-gap units are affected by conditions such as humidity, and in general, vary tremendously from calibrated settings soon after being serviced.
Probably the most demanding electrosurgical procedure with respect to the output of the generator is a transurethral resection. We have measured voltages and current for various surgical procedures.1 Whatever the procedure, the larger solid state units have sufficient capacity and, like other solid state electronic components, demonstrate little fluctuation in performance over a long period of time. This is not to say that a poorly designed solid-state generator is better than a well-designed tubed model. Spark-gap units, however, are notoriously unreliable, and I know of no clinical circumstance in which they