Surface tension is so delicate that I think it must be difficult to measure. I recall easy ways for us to observe it:
* needle (or 2-edge razor blade) rests on top of water
* water level in a full glass bulges higher than the rim of the glass
* water forms drops as small stream falls from faucet,
* water drops become spherical
* insects called water striders skate on water surface.
The springy quality of surface tension is what needs to be detected.
A sensor needs to be delicate so it can measure the weak springy force.
Its sensing method needs to ignore viscosity of liquid.
If you make your own, its results should be an objective measurement (if possible). It sounds more professional if you state a number of units, rather than saying 'surface supported 4 razor blades before they all sank.'