What is the difference between the FOGRod and the Multitrode^® “probe”?

Both units work on exactly the same principle. But there are some significant differences:
a) Toughness – the FOGRod has been designed to withstand a lot more impact than the Multitrode^® probe. You can see a video of the FOGRod being thrown up into the air and bouncing off concrete without cracking. This is due to a number of factors including better design and better materials.
b) Shielded cable – modern instruments have shielded cable to avoid noise, e.g. from motors, affecting their measurements. The FOGRod has a shielded cable, whereas the Multitrode probe does not.
c) Cable integrity – the FOGRod cable is inherently tougher due to its braided shield, but it also has a failsafe core, which allows the LIT to test for cable breaks and cable short-circuits.
d) Price – the FOGRod is about half the price of the Multitrode “probe”.