Chapter 2 Operation
2-10
2.7 Rate/Thickness or Frequency Display
The SQM-160 determines deposition rate and thickness by measuring the frequency
shift of a crystal oscillator over time. In some applications, the actual crystal frequency
is desired. Displaying crystal frequency can also be useful in troubleshooting sensor
operation.
To select Rate/Thickness, or Frequency displays:
1. Press Program to enter program mode.
2. Press Prev to enter the System Parameters Menu
3. Press Next until FRQ DISP is shown.
4. Turn the Control Knob left or right to select the desired display mode.
5. Depress the Control Knob to accept the value.
6. Press Program to exit the System Parameters Menu and return to normal mode.
2.8 Crystal Life Display
The SQM-160 calculates the remaining crystal life based on the FMin/Max values set in
the System Parameters Menu (see Section 2.5).
To display the remaining crystal life for the sensors used by the currently active film:
1. Press the Xtal Life switch in the front panel Control section.
2. The sensor is shown in Display 1, the % remaining life, is shown in Display2.
3. Turn the Control Knob to display the % life of other sensors active for this film.
4. Press Xtal Life to return to normal rate/thickness, or frequency display.
Note: You cannot enter program mode while the crystal life display is active.