Questions about Relay and ORP probe

I am new to electronics and looking for an ORP probe on Aliexpress for water quality management.

It looks like all of them(for example) don't come with the module. And I know the probe outputs analog signals.

The pH probes on Ali however all come with amodule. Does it mean ORP probe use a general module that I have to buy separately?

For Relay, if I would like to control 12V AND 240V devices, will (this) should serve the purpose? I am not sure if 12V and 240V require their own Relay(12V Relay, 240V Relay).

Looking at those pages , the problem is the specification gives no real detail of the output signal type , accuracy etc .
I’d suggest you look for how an ORP works ( google ) and that might give you a clue .

Someone on here may be along who has used one of these .
If you have little experience I would not advise you switch mains voltages -you need to know what you will be switching in terms of current , ACor DC , inductance to determine which relay to use .
You also need to figure how you will supply power to operate the coil , which must be compatible , voltage wise, with how you are powering it .
I’d suggest seeking out some basic guide s on this ( there are some on this site ).
But again don’t build mains voltage stuff unless you have the right experience .