The probe holds a very important position in a composition os the force tensiometer. The force depends on the following factors: size and shape of the probe, contact angle between the probe and the liquid, and the surface tension of the liquid. There are 2 commonly used types of probes for force tensiometers ; the du Noüy ring and the Wilhelmy plate. A metal rod can also be used instead of a Wilhelmy plate when sample volume is limited.
Sigma Series

Sigma CMC
Fully automated critical micelle concentration (CMC) determination w high accuracy

Sigma 700/701
Wilhemy plate / Du Noüy tensiometer with versatility.

Sigma 702
Platinum Du Noüy ring, Platinum Wilhelmy tensiometer

Sigma 702ET
702 made dedicated for oil analysation