Quartz Crystal Microbalance Digital Controller

viOverviewPARAMETER and VALUE keysThe PARAMETER and VALUE keys on the QCM200 are used to (1) select displaymodes, (2) program instrument settings and (3) zero the Relative Resistance (r) andRelative Frequency (f) readings.Use these keys to navigate through the menu system. The PARAMETER key jumps tothe next parameter and the VALUE key selects the next available value for the currentparameter. The VALUE key walks through the circular list of possible values for thecurrent parameter. The displayed value becomes active immediately. Pressing thePARAMETER key stores the new value and moves the menu display to the nextparameter.Relative MeasurementsHold down the VALUE key for 2 seconds while in the Absolute or Relative Resistancedisplay modes to (1) set the Resistance Offset to the current Absolute Resistance valueand (2) zero the Relative Resistance readings. Hold down the VALUE key for 2 secondswhile in any other display mode to (1) set the Frequency Offset to the current AbsoluteFrequency value and (2) zero the Relative Frequency readings. The ZERO LED flashesto indicate zeroing of the Relative Frequency or Relative Resistance displays.Frequency Output ConnectorThe Frequency Output connector outputs the crystal oscillator frequency. The signal hasTTL (square wave) levels and a source resistance of 50 . Use this output to connect toan external frequency counter (optional). The BNC shield is connected to chassis ground.Conductance Output ConnectorThe Conductance Output connector outputs the conductance signal (V c ), related to theseries resonance resistance of the QCM crystal by:= 10,00010V c5R 75Voltage levels span 0 to 10.625 VDC and the source impedance is 1 k. Use this outputto connect to an external high precision multimeter (optional). The BNC shield isconnected to chassis ground.QCM200 Quartz Crystal Microbalance