SRS QCM-200 Crystals for Liquid Monitoring
These 1” diameter AT cut polished quartz crystal sensors are compatible with Maxtek PM 700 series, RQCM monitors, PLO-10i,
and Stanford Research Systems (SRS) QCM100 QCM200 and EQCM quartz crystal microbalance systems.
Essentially, these are AT-cut crystals very much like standard vacuum monitor crystals, with four exceptions:
- the diameter is larger, allowing for a very clean resonance spectrum and resulting measurement stability.
- the crystals are flat, unlike the planoconvex design of a vacuum monitor blank.
- the crystals are often polished on both sides, to minimize the “dragging” of water by the crystal surface during oscillation and 4) the electrode pattern is a wrap around design, which means that the crystal can be completely contacted electrically from one side. This latter feature is a necessity since the crystal sensor head must be submerged in water. An O-ring seal is incorporated in liquid monitor sensor heads to prevent electrical shorting.