Contact Angle Meter

Holmarc's Contact Angle Meter (Model No: HO-IAD-CAM-01) is a compact and cost effective CMOS based instrument for measuring contact angles of liquids over solid substrates. It has manual dispensing unit with camera interface for measuring contact angle of liquids on solid surfaces. The surface over which contact angle is to be measured is held in horizontal position to find out contact angle using sessile drop method.

State-of-the-art optics, precise opto-mechanics, high-resolution CMOS detector and associated electronics used in our instrument guarantee stable and accurate measurements. The illumination intensity of the back light LED can be controlled.. The surface over which contact angle is to be measured can be rotated through 180 degree from its horizontal position for advanced contact angle study and to find out contact angle hysteresis.

The wettability of a droplet is also dependent on the substrate in contact with the liquid. We provide 3 different substrates along with the equipment - made of aluminium, brass and stainless steel. However, the substrate according to customers’ choice can also be loaded into the equipment.

Standard off the shelf syringes can be integrated from 0.4 to 20 ml, from any manufacturer. The equipment is compatible with glass, plastic and SS syringes. Three chromatographic syringes with 50 micro litre, 100 micro litre and 250 micro litre capacity are supplied along with the equipment.

Experiment:

To measure the contact angle of liquids over various solids.

If H represents the protruding height of droplet and D the diameter of the lens, then the contact angle θ is defined by geometry as,

θ  =  2 arc tan ( 2H / D )

This is the angle formed by a tangent to the droplet at the point the liquid surface meets the supporting block.

Specifications:

Measuring method	:	Sessile drop method
Analysis method	:	Automatic curve fit analysis using drop snake method.
Optics	:	High performance aberration corrected imaging lens with precise manual focus adjustment.
Camera type and FPS	:	CMOS Sensor
Image Resolution in Pixels	:	2592 x 1944
Video system	:	High performance CMOS Sensor. 3m shielded USB cable included.
Video Resolution in Pixels	:	640 x 480 at 17 fps ,    1280 x 960 at 10 fps
		1920 x 1080 at 9 fps ,    2048 x 1536 at 6 fps
		2592 x 1944 at 4 fps
Lighting	:	LED Based diffused lighting mechanism.
Dispenser	:	Mechanical dispenser with precise control.
Dimension	:	350 x 125 x 350 mm
Weight	:	30 kg (approx)
Power supply	:	230VAC, 50 Hz. / 110V AC, 60Hz (Optional)
Other specifications	:	15 mm height adjustment for Sample holder.
		180 degree rotation for the sample holder.
		75 mm XY travel provided for the CMOS - optics assembly.
		Rotatable screws provided beneath the base for levelling purpose.
# Laptop is not in scope of supply

Drawings:

Technical Highlights:

1.    White light LED with variable intensity control ensures extreme low heat radiation.

2.    Precise travel adjustment provided for CMOS with Optics assembly to fine focus the image.

3.    Manual dispensing.

4.    50, 100 & 250 micro liter sample syringes provided with the system.

5.    Precision height adjustment provided at the test base.

6.    Vibration inhibiting solid construction for sharp drop images.

7.    Powerful and user friendly windows software provided for image analysis.

8.    Live images can be viewed on the PC monitor showing the droplet on the solid surface reassures the operator-regarding validity of the contact angle measurement.

9.    Video processing enabled software.

10.    Captured image and its Angle measurement table can be saved for future reference.

Contact angle is the angle formed by a liquid at the phase boundary where a liquid, gas and solid intersect. The shape of the drop is controlled by the three forces of interfacial tension. Static Angle and Advancing Angle are quantitative measures of the wetting of a solid by the liquid, but they can also be used as a quality control measure in surface treatments and surface cleanliness. Receding Angle is a quantitative measure of the adhesion of a solid to a liquid.