Is the ground resistance meter indispensable when grounding your home?
If the utility neutral breaks you're up against the ground (i.e earth, dirt, soil, water, rocks) being a relatively terrible conductor as compared to a metal wire, so the various tests involving testing the ground with a heavy load between hot and ground are highly dubious.

In the USA, the NEC (our local code, presumably not what applies in Brazil) requires either a ground test (time consuming, expensive meter) or two ground rods 8 feet or more apart, minimum. Many places have also implemented code requiring that in new construction the concrete foundation should include a "Ufer" ground or basically have the reinforcing steel tied into the grounding system, which is a far more effective connection to earth ground than ground rods in almost all soil conditions. 

As a result, few electricians here bother to own the expensive meter, and most services have two (or more) ground rods 8 (or more) feet apart; Or one foundation ground (concrete encased electrode) and one ground rod.