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raffaele.battaglia

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raffaele.battaglia
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  • Hi Shabana, we decided to use 10 MHz due to their higher sensitivity. Also, undersampling works very well right at those frequencies. The new system that we will launch within few days (openQCM Wi2) will use a Teensy 3.2 board as well as the integra…
  • You are welcome. In any case for completeness see the attached photo taken with the oscilloscope. As you can verify the signal output from the shield of openQCM, despite the datasheet of SN74LVC1GX04 declares a square wave is really similar to a "…
  • Hi Shabana, thank you for your interesting question and sorry for my reply delay. We use the original freq_count library without any changes. Unsampling is automatically processed by Arduino. To explain me better, I will give you an example. Arduino…
  • Hi schurli111 , openQCM use a quartz driver (SN74LVC1GX04) that can nominally operate between few KHz up to 28 MHZ. With external component it is a true pierce scheme circuit that "link" to the parallel resonance of every quartz in the described fre…
  • Hello jmhm, thank you for your interesting question. Unfortunately you will not be able to retrieve a frequency-mass relation for a such "big" droplet by measn QCM devices. First (but secondary as importance) the nominal saturation limit for a 10MHz…
  • Hi Nhannd, thank you very much for your evaluations. In this first version of openQCM shield we preferred to choice a basic approach. In this way we decided to make an electronic for general applications. But your evidences are absolutely correct. …
  • Yes, but consider that the teflon cell is strickly linked to the openQCM case design. The teflon cell is a cover piece with 2 fluidic interfaces for connecting pump tubes, embedded in the opeQCM cover. I believe that is not useful without the rest o…
  • Hi Claire, In the past I worked with UHV environments for aerospace applications and actually QCM technology is one of the best and reliable methods in order to monitor mass variations at molecular scale, under vacuum and also in cryogenic environm…
  • Dear Michael, I am very sorry for the reply delay. In this period we are working hard around openQCM dissipation module and as a consequence I lost this post! I know about people that used the shield in vacuum, but personally I do not received fee…
  • openQCM quartz is not grounded. Honestly I do know if it is possible to apply a DC offset.... let me to try before better answer to your question.
  • Hi mswestph, this is Raffaele, from openQCm Team. I used cold fingers and QCMs in UHV during my Ph.D. thesis. I used this method in order to increase cleaning of the sensor and in order to avoid molecular degassing from the sensor. In my case I do …
  • Generally we used a flow rate of about 0.1 ml / min Which causes a frequency standard deviation of about 3 Hz to flow . The maximum flow rate Should be 1 mL / min Higher flow rate can cause larger frequency fluctuations around the baseline . But it …
  • Hi Nicole.g, Arduino micro clock is 16 MHz and FreqCount library works well up to 8 MHz as you can read here http://www.pjrc.com/teensy/td_libs_FreqCount.html > FreqCount: best for 1 kHz to 8 MHz Despite this Arduino clock limit, we can measu…
  • You are welcome and happy New Year too!!!
  • Dear Stuart, This is Raffaele from openQCM team, very nice to meet you. First of all thank you for being our welcome customer. Here my answers: 1. technical specifications of openQCM quartz crystal sensors in Sauerbrey's equation electrode a…
  • Hi Terry, the openQCM has an embedded thermistor for monitoring the temperature of the device. In this way you can check when the device reaches the temperature stability, i.e. the temperature reaches the plateau, before starting your measurement. B…