Appendix H Comparison of output voltage per unit weight of resistivity meters
a) "Super" MiniRes (s/n >99 & < 141) is 720 Vpp / 4.3 Kg = 167 Vpp per Kg
b) Lippman is 80 Vpp / .75 Kg = 107 Vpp per Kg
c) STING 800 Vpp / 6.6 Kg = 121 Vpp per Kg
d) IRIS (SYSCAL R1 PLUS) 800 Vpp / 9.5 Kg = 84.2 Vpp per Kg
e) Syscal Junior 800 Vpp / 7 Kg = 114.3 Vpp per Kg
f) Terrameter SAS 300C 320 Vpp / 5.6 Kg = 57.1 Vpp per Kg
The MiniRes is the clear winner in terms of output voltage per unit weight. This is NOT an accident, nor is it due to flimsy, lightweight construction. One of the main reasons for the MiniRes being so lightweight is because of its High Voltage architecture - it is an architecture designed by a person named Royer. The ideal thing about it is that it allows complete saturation of the B-H magnetic curve of the high voltage transformer on negative AND positive excursions. Thus, you can get a much larger voltage swing with a lot smaller mass of ferrite. The STING uses the conventional flyback technology. Conventional flyback technology allows only one half of the B-H magnetizing curve to be utilized. It typically requires twice the mass of ferrite that the Royer technology uses.
Modern electrical engineers choose the Royer technology for the high voltage supply for driving the cold fluorescent lamps on laptop computers. The flyback technology is too heavy for this high voltage application in laptops.