The Stanford Research Systems QCM200 is a standalone quartz crystal microbalance instrument that measures mass deposition and viscoelastic properties with nanogram sensitivity and sub-monolayer detection capability. Operating at 5 MHz with an AT-cut, 1-inch diameter plano-plano crystal, the QCM200 directly correlates resonant frequency shifts to surface mass changes while simultaneously monitoring crystal resistance to characterize film and liquid viscoelasticity. The instrument handles highly viscous media up to 88% glycerol concentration, making it suitable for both air and liquid-phase measurements.
Technical Specifications
• Quartz Crystal: 5 MHz AT-cut, 1-inch plano-plano, standard Cr/Au electrodes with optional Ti/Au, Ti/Pt, or In Sn oxide configurations
• Frequency Counter: Integrated, user-selectable gate times (0.1 s, 1 s, 10 s) with display resolution of 1.0 Hz, 0.1 Hz, and 0.01 Hz respectively
• Timebase Stability: <4 × 10⁻⁹ Allan Variance (typical); Accuracy: ±1.5 ppm
• Resistance Meter: 0 to 5000 Ω range with resolution of 0.001 Ω (R < 100 Ω), 0.01 Ω (100–1000 Ω), and 0.1 Ω (1000–5000 Ω)
• Frequency Output: 5 MHz TTL square wave, 50 Ω source impedance
• Δf Analog Output: ±10 V full scale, 20-bit resolution; selectable ranges from ±200 kHz to ±2 kHz; 1 kΩ source impedance
• Conductance Output: Log-scale voltage output (0 to 10.625 VDC) correlating to resistance
• External Timebase Input: 10 MHz, 1 Vpp nominal, 1 kΩ input impedance for phase-locking to external precision references
• Capacitance Cancellation: Integrated shunt-capacitance cancellation circuitry
• Crystal Isolation: Transformer-isolated crystal for EQCM compatibility
– Key Features
• Dual integrated measurement system: frequency and resistance simultaneously
• Front-panel or RS-232 control via Windows/Mac software for real-time acquisition and analysis
• Potentiostat integration through analog outputs for electrochemical applications
• Supports nanogram to microgram mass detection ranges
– Typical Applications
• Electrochemical quartz crystal microbalance (EQCM) studies
• Thin-film characterization and viscoelastic analysis
• Molecular-level gravimetric sensing
• Lossy film and high-viscosity media measurements
– Compatibility & Integration
Analog outputs interface directly with potentiostats. External 10 MHz precision timebase input enables enhanced frequency stability for long-term measurements.
