The Opal NFXI-TDIFF uses the same thermistor and microprocessor technology to provide an alarm when the rate of rise in temperature exceeds 10°C/minute (typical) or if the temperature exceeds a threshold of 58°C (Response Class A1R). Notifier’s Opal protocol allows it to be software configured to be either a fixed 58°C, a fixed 78°C unit or a 58°C with rate of rise device. The sensing element is panel controllable through the Opal Protocol so the sensitivity thresholds of each element can be changed by the panel offering the ability to customise the device for the changing use of the area it is protecting. The detector has built in short circuit isolation and two integral tri-colour LEDs that provide 360° local visual indication of the device status. The LEDs are programmable with static or blinking red, amber and green status indications available.