How many Ω should the ground resistance of PCBA-related equipment be controlled?

Dear experts, I would like to ask: The equipment that produces PCBA products (such as printing presses, SMT machines, reflux furnaces, AOI, wave soldering furnaces, etc.), their grounding resistance should be controlled within how many Ω? Is there a standard basis or explanation?

There is a standard practice, SP10.1 that may help with machines. It describes several methods on how to evaluate equipment. This is an old standard practice and will be incorporated into SP17.1 or a new standard practice 17.X. It is recommended that all metal parts in the machine that comes into contact with ESDS items be grounded at 1 ohm or less but it is not a requirement of any standard.