I have an old Tek Mate that stays in the tool box, a ***** D-Tek, a CO2 D-Tek and a large bottle of soapy water.

The last three are all very reliable tho the two D-Teks take a little practice - just remember to move the tip in a slow deliberate manor and they find almost every leak first time.

I do still use a halide lamp for R22, but tend to use that only when the leak is large, difused and causes background levels to be high enough to confuse the electronic units.

Regards
Steve