The module is typically used in applications like photovoltaics. Onto the glass of the window module, a platinum ring electrode has been sputtered, which acts as a counter electrode (CE). The top electrode of an ordinary sensor acts as working electrode (WE). The reference electrode (RE) is placed in the outlet flow path. The window allows optical access to the WE. The standard configuration includes Viton O-rings, but this can be upgraded to Kalrez to enable work with more harsh chemicals.


General specifications
Compatibility Compatible with all QSense sensors, QSense Explorer, Analyzer and Pro (via an add-on Explorer chamber)
Internal volume 100 μl (above the sensor)
Type of measurements  Flow or stagnant liquid measurements
Glass 1 mm thick Sapphire
Window dimensions 16.6 mm x 7.2 mm
Materials exposed to the liquid Titanium (flow path), Sapphire (glass), platinum (counter electrode), Viton®
(standard O-ring) or Kalrez® (high resistance O-rings) and Polyurethane-based polymer (reference electrode)
Maximum temperature 40 °C
Working distance 3.3 mm
Bench to objective distance 33 mm
Cleaning All parts may be disassembled for separate cleaning, except the module base contacting the chamber platform
Dimensions Height: 32 mm; Width: 35 mm; Depth: 63 mm
Delivered with: all necessary accessories including cables and fittings.
* Notes on potentiostat:
1. Potentiostat needs to be fitted with 4 mm lab plug connectors.
2. Floating-ground capacity is a benefit but not required.
3. QWEM 401 module design limits the operation range of EIS to a maximum frequency around 10-100 kHz.
Working electrode The QCM-D sensor itself
Counter electrode Platinum ring, Electrode area: 69.6 mm²
Reference electrode  World Precision Instruments low leakage , Dri-Ref-2SH*
Ag/AgCl, 3M KCl
Alternative reference electrodes can be used as long as they fit the diameter of the mounting hole.
Sensor (WE)
Fundamental frequency ~5 MHz
Electrode area exposed to electrolyte 0.97 cm2 (Ø 11.1 mm)
Thickness (sensor + Au) 340 µm
Roughness of optically polished electrode surface < 3 nm (RMS)
Dri-Ref 2SH (RE)
Length 2.54 cm (1.2 in.)
Diameter 2 mm
Construction  Isoplast™
Liquid Junction Frit Vycor
Lead length 76 cm (30 in.)
Connector 2 mm pin
Resistance (typical) 2.7 KΩ
Filling Solution KCI
Leakage (mL/hr) ~5.7x10-8
* For further information about Dri-Ref-2SH, refer to World Precision Instrument’s webpage: www.wpiinc.com



  • All QSense sensors
  • QSense Explorer
  • QSense Analyzer
  • QSense Pro (via an add-on Explorer chamber)