@fixjunk this configuration will be supplied to your gateway from a controller. Source: https://www.mysensors.org/download/serial_api_20 When your MySesnors node boots up, sends a I_CONFIG request to your controller, your controller has to respond to this request [response can be either (M)etric or (I)mperal ] AFAIK, This metric change will not affect your sensor measurement units. You have to convert yourself in your sketch. @mfalkvidd can confirm this.