REI CMA-100 - Manual (Page 9)

recommended to apply a DC bias voltage to activate any potential microphones. The DC
Bias Voltage should only be used after ensuring that the line does not have an active
USING THE CMA: REI
voltage supply. Then, the DC Bias voltage can be switched on and the control knob
slowly turned to both negative and positive directions while listening with the
headphones to see if a microphone is activated.
Using the CMA with other probes
The CMA can be connected to a variety of other probes.
• Inductive coil - for coupling to an audio signal without making a metallic
connection.
• Contact microphone - for detecting sound within physical structures.
Over voltage protection
If the CMA's input voltage limit is exceeded, then damage will most likely occur that will
make the CMA require repairs. The CMA case is isolated from an input up to 500V.
Therefore, if the input is allowed to exceed 500 volts then a shock hazard will exist.
Over current protection
When connected to an AC power line, the BIAS GENERATOR should not be activated.
In the event that it is, there are input current limiting devices that will protect the delicate
parts of the CMA. After disconnecting the input, it will take several seconds for the
CMA to work properly again.