Sigma Instruments Test Crystal 5.5 MHz BNC Thin Film Deposition Thickness Monitor
New, see photos.
From the manufacturer on how to use it: "If the % Life reading is not correct [on your film thickness monitor], remove the 6” BNC that is connected to your feedthrough at the oscillator. Connect the test crystal and adapter to the oscillator connector labeled feedthrough. For a typical setup of 6MHz Max Frequency and 5MHz Min Frequency, the % life display should be near 50%."
