Video based, optical surface/interfacial & contact angle measuring device PAT1

Software controlled measurement and analysis of the static and dynamic surface/interfacial tension, static and dynamic contact angle according to the “Sessile & Captive Drop-method“ as well as the shape of “Pendant drops“. Surface rheological studies to measure the dilational elasticity and viscosity. Determination of the wettability of solid surfaces, the surface free energy of solids and other components and the calculation of the surface and interfacial tension based on the analysis of the drop/bubble shape

Consisting of:

• basic platform on which all parts are safely mounted
• automatically controlled dosing system
• adjustable temperature controlled measuring cell
  (low temperature range 10 to 80 °C, optional : high temperature range 10 to 1000 °C)
• CCD-camera with fixed objectives
• high-performance frame grabber installed in the PC
• back lighting with continuously adjustable intensity
• power supply

Technical data:

• Size of the device ( L x W x H ): 700 x 240 x 250 mm
• Weight: 15 kg
• Optics:
• CCD-Camera:
• 1/3-inch interline transfer CCD image sensor
• Resolution 752(H)x582(V) pixels, Interline Transfer CCD
• Scanning Area 4.9(H)x3.7(V) mm or 4.9(V)x3.7(H) mm
• Auto Light Control (ALC) / Electronic Light Control (ELC)
• Back Light Compensation
• Signal-to-noise ratio 50dB
• Optical distortion <0.05%
• C-mount
• Objective:
• Fix objective
• Magnification 0.5x…4.5x with extension tubes
• Image processing:
• PCI-frame grabber board with 132 Mbyte/s max. Data transfer rate (compatible to Euro-Norm: CCIR and US-Norm: RS-170)
•  Light: Could LED light source
• Dosing system:
  Resolution: 3000 steps
  Work way: 30 mm
  Precision: <1.0% at full stroke
  Interface: RS232 
• Range of contact angle measuring: 10…180° ; up to ±0.3° reading accuracy
• Measuring range of surface and interfacial tension: 1…1,000 mN/m; ±0.1 mN/m
• Power supply: 100…240 VAC; 50…60 Hz; 55 VA

Main features of the software:

• on-line interfacial tension/contact angle calculation
• control of the dosing system for definite changes of a drop or bubble (transient or harmonic changes)
• control of a piezo unit (additional equipment)
• active control loop for keeping constant either the volume, the area, or the height of a drop or bubble
• calculation of the surface free energy of solids according to the equation of state by Li and Neumann calculation of the dilation rheological parameters from relaxation measurements