Product specification MO 2000 Set and

Sennheiser Electronic Corporation
1 Enterprise Dr • Old Lyme, CT 06371
[phone]
APPLICATIONS:
Industrial applications - Possible applications for the optical microphone include the acoustic monitoring of power utility
plants (including hydroelectric, wind, and nuclear plants), as well as oil and natural gas production facilities. In this
example, the microphone would “hear” slow leaks, which, due to their small size, cause neither a pressure loss nor an
alarm message in other monitoring systems.
Medical applications - The microphone is ideal for use in magnetoencephalography (MEG) and magnetic resonance
imaging (MRI). For example, it maintains communication with the patient during MRI scans or achieves active noise
cancellation within the MRI machine. The optical microphone does not disturb the imaging process and is itself not
influenced by the strong fields inside MRI equipment.
Measuring applications - The microphone is ideal for use in EMI/EMC laboratories, as it does not influence the electric
field. In this case, for example, it functions like an ear on a cellular phone.
An optical principle is the only microphone principle in which the microphone head and electronics can be located far
away from each other. The optical microphone relies on light from an LED, which is directed onto a reflective diaphragm
via a fiber-optic cable (optical transmitter waveguide). The membrane then reflects part of the light into an optical
receiver waveguide. If the diaphragm is moved by sound signals, the reflected light beam is displaced, allowing more or
less light into the receiver waveguide. At the end of the receiver waveguide, a photodiode converts the light intensity
variations into electric signals.
HOW IT WORKS
Optical Microphone Systems
MO 2000 Set and IAS MO 2000 Set