The model IRD7111 is designed for continuous measurement of environmental noise in industrial and urban applications. It is suitable to meet Occupational Health Regulations that requires precise sound level monitoring. It continuously transmits signals to a Central Control Room giving warning and alarm of excessive noise that could be a health hazard to personnel in the area.

The IRD7111 is microprocessor based and programmable for a range of sound pressure levels. In addition to its 4-20mA output and relays, IRD7111 has a BNC socket for FFT analysis of the raw time wave form signal for identification of any specific sound frequencies that may be harmful. IRD7111 is part of IRD Mechanalysis Ltd’s comprehensive IRD7000 suite of proven site mounted machinery vibration and TSI transmitters

The IRD7111 is designed to be mounted above process machinery offering a 90 degree sound cone radius below. The base mounted integral microphone is protected from dust and moisture ingress for long life. Once programmed, the hinged door is screwed sealed closed as the enclosure is IP65 rated. Standard instrumentation 4­-20mA signal data can be transmitted to a Central Control Room or DCS for trending, recording or for local display. Internal relays are provided for audible annunciation or visual alarms. Prior to installation a sound survey would be undertaken to establish an optimum location for IRD7111. Based on machine distance from the microphone the appropriate db warning and alarm levels can be set. The IRD7111 is also provided with ‘FAST’ option to select Peak Measurement, if required. The transmitter’s output current is 4mA DC (when the input sound signal corresponds to the base threshold) and 20mA DC (when input sound level corresponds to full scale) with an accuracy of ± 2dB of full scale range.