Calibration of the probe tube
In principle all probe tubes from ProbeTube.com have the same characteristics. It is however important to know for sure that the probe tube won’t cause any deviation in the results of the measurement. Therefore, REM tubes must be calibrated before each measurement.
To perform this calibration process, the end of the measurement probe is placed close to the reference microphone. The sound that both microphones now pick up is exactly the same. By starting the calibration process, a noise is generated by the REM-module’s loudspeaker which is picked up by the two microphones. If there is a difference between the two microphone signals, the software will compensate for this by the calibration.
Checking the calibration
After the calibration is finished this can be checked with a REUG measurement. This should provide a flat line result showing 0 dB amplification. The REUG-measurement is described in more detail in one of the following chapters.
When the calibration of the probe tube is successful the actual measurement can start.