Refrigerant Leak Detector with Heated Diode

I have been looking at refrigerant leak detectors and would like to know which is better, heated diode or corona discharge?

When choosing an electronic refrigerant leak detector, there are essentially two different technologies available on the market today. They are corona discharge and heated diode. A corona discharge detector works when the corona barrier is broken by the presence of refrigerant. It can also be broken by dust and moisture for example. In the past, Corona discharge refrigerant leak detectors worked great on R12 and R22 systems but with the advent of R134 they were more inaccurate than a heated diode refrigerant leak detector. They still work with R134 but most people have much better luck using a leak detector with a heated diode. Here is an example of a refrigerant leak detector with a heated diode.