Flameproof Duct Humidity Temperature Transmitters AI-RHTx-FLP are designed for HVAC applications for simultaneous dual analog 4-20mA outputs corresponding to temperature & humidity. The Flameproof Duct Humidity Temperature Transmitter is ideal for connecting outputs onto BMS/PLC/SCADA since it provides industry standard 4-20mA Analog Outputs & also comes with optional RS 485 Modbus communication.