Chronoskop CHR-9 Timegrapher
User manual
www.CHRONOSKOP.com
12
Measurement with the external acoustic crocodile microphone
The external crocodile microphone belongs to the optional accessories and can be ordered
separately.
For acoustic measurement, an external piezo microphone from the optional accessories can
be used. This is to be connected to the 3.5 mm microphone jack. When plugging in the
microphone plug, the built-in microphone is automatically deactivated. The crocodile
microphone is to be clamped to the watch case. It is particularly suitable for measuring
mechanisms of large clocks. For acoustic measurements of clocks with percussion the
percussion should be switched off to avoid noise. Microphones connected to the external
power supply are not allowed to be used.
The crocodile microphone gives a lot of flexibility and is very useful when measuring a clock
in different positions. It is characterized by very good decoupling from the ambient
noise.
External crocodile microphone
Adjustment of microphone sensitivity
The "Sensitivity" rotary knob allows you to adjust the sensitivity of the piezo microphone. It
should be noted that neither minimum nor maximum microphone sensitivity leads to optimum
signal processing. The best result is usually achieved approximately in the middle position of
the rotation. The sensitivity should be set until every single measuring pulse is clearly
recognizable in the "Time axis" display mode. Noisy noise (such as fan noise in the PC)
should be avoided. This noise is not visible in the time scale display, but reduces the
sensitivity of the amplifier electronics significantly.
