External Temperature Monitoring

I have a Temperature Sensor & Gateway monitor. Running Firmware 7.41. How do I add and/or change the sensor to monitor the external temperature? It currently monitors the internal temperature of the device? The temp displayed is off from the actual room temperature.

Gamecock

what do you mean its off? when you plug the external temperature to the gateway you should now have 2 temperature sensors.. now if you meant that what you have is only a gateway which has a built in temperature sensor then it will detect the temperature on where it is placed.