No, it won't work properly. You cannot "plug off" the high side. Which ever port is not connected to the tank needs to be open to atmosphere.

In our area, we need to put a scintered filter, like those used in hydraulics, to keep the bugs out which will build nests in the open port.

How you configure it depends on whether the 4-20mA output rises or falls with higher vacuum and if there's an integral meter, whether the values are positive or negative.

I would have connected the high side to the tank and left the low side open to atmosphere, but that's me.