Quartz crystal fand oscillator driver frequency
Hi everybody,
I know that the frequency of the quartz crystal frequency is one of the most important consideration for QCM.
The chosen frequency must be the same as oscillator driver but in what proportion ?
What can be the maximum difference between them without an impact on signal ?
Thanks to all Openqcm's team and thank you for setting up this forum.
Have a good week.
Kind regards,
Bob
I know that the frequency of the quartz crystal frequency is one of the most important consideration for QCM.
The chosen frequency must be the same as oscillator driver but in what proportion ?
What can be the maximum difference between them without an impact on signal ?
Thanks to all Openqcm's team and thank you for setting up this forum.
Have a good week.
Kind regards,
Bob
Comments
thank you for your question. This is a challenging question!
The resonance frequency is the most important parameter of a Quartz Crystal Microbalance. The chosen frequency does not have to be necessarily identical to the oscillator driver (or better it depends on the method you wil use). As matter of fact in the case of openQCM we use a Pierce oscillator circuit that is able to drive the quartz between some KHz up to 28 MHz. The situation could be drastically different if you will use a DDS Module. In this last case, effectively you have to actuate the quartz at the same frequency of the resonant element. Alternatively you could use an excitation by means an impulse and this last method will "nominally" contemporary excite all possible frequencies.
Bob.