Not a myth. Anything connected to the base unit will use the base unit temp for compensation, PM modules use their own temp probe for compensation. If you don't have a temp probe connected to the PM module, do not enable temp compensation.Apparently, the Same Module is a myth?
Well, I change my R-pH to my Base Unit and Revert my CRx_pH to PM1.
But TC on Base Probe & PM1 Probe is connected.
Because when I turned TC of R-pH, my PM1 probe is automatically Enabled TC on its own. If I Disabled TC on PM1, the TC on Base Unit probe is also disable TC. So they actually linked.
But how does one calibrate Tmp?
I have multiple PM1 and PM2 modules in my tanks and some of them have TC enabled and some don't. They are not linked.
The best way to calibrate temp probes is to get a NIST traceable thermometer (I use the $30 Cole palmer stick pen) and then calibrate all your temp probes (and heaters if they can) to match the traceable thermometer.