FAQ - SITA Tensiometer

Bubble pressure tensiometers allow uncomplicated measuring of the dynamic surface tension even from a small sample. The wide range of the adjustable surface age (bubble lifetime) enables an analysis of the kinetic characteristics of surface active components in the liquid. The interface(air/sample) which is crucial for measuring does not have to be cleaned after reading (e.i. like a Du Noüy-Ring) because with every new bubble the interface is freshly created.

SITA tensiometer are easy to handle and functions are adjusted to their respective applications.

The measuring values of all SITA bubble pressure tensiometer (SITA DynoTester+, SITA pro line t15, SITA science line t60/t100 oder SITA clean line ST) are comparable to each other. Thus, measuring results achived in research can be used even in process monitoring. This is unique in the market of bubble pressure tensiometer.

SITA bubble pressure tensiometer don't depend on the immersion depth. Therefore, the handeling is very uncomplicated. Also, the density of the liquid being measured (often unknown) does not have to be determined and entered prior to measuring.

The devices differentiate by their function and measuring range. To optimally combine your requirements with your budget our engineers will gladly adcice and assist you.

The hand-held measuring devices work independently. All measured variables such as surface tension, temperature, bubble frequency and bubble lifetime (surface age) are automatically measured and stored within the device (SITA DynoTester+, SITA pro line t15, SITA science line t60/t100).

The available windows software additionally allows:

• comfortable adjusting and controlling of the device using standard windows elements,
• easy data analysis, editing and printing of all measurements as well as
• saving of data in common file formats.

No, while developing the instruments we attached importance to easy operation. A special training is not necessary. The basic functions such as

• ONLINE measuring (permanent measurement at constant surface age) and
• AUTO measurement (measurement with an automatically increasing surface age)

are started by pressing the respective press. Naturally, a minimum of adequate care, knowledge and experience for solving the measuring problem is necessary.

The standard capillary is made of PEEK™. In contrast to teflon this synthetic is firmly wettable and thus, guarantees reproductable and drift-free measuring values. PEEK™ has a high thermo-resistance, a good resistance against highly concentrated alkali, non oxidized acids and solvents as well as a superb hydrolysis resistance against boiling water.
If required we offer teflon capillaries and glas capillaries for special problems as well.

After changing the capillary start an automatic calibration using water. After that the device is ready to measure.

To clean the capillary the clean mode (clean-button) is used. In this mode a maximum air flows through the capillary. Thereby, particles and fluff that might have settled in the capillary during use are removed. For better cleaning results we recommend to additionally immerse the tip of the capillary into a ultrasonic cleaning bath using a solvent that is correspondent to the previous sample. Please do avoid submerging the whole capillary. The time the capillary needs to remain in the cleaning bath depends on how dirty it is.

• SITA science line t100: ca. 8 hours (integrated Li-Ion battery, charge via USB or mains adapter)
• SITA science line t60: ca. 3 hours (batteries AA of your choice)
• SITA DynoTester+: ca. 8 hours (integrated Li-Ion battery, charge via USB or mains adapter)
• SITA pro line t15: ca. 8 hours (integrated Li-Ion battery, charge via USB or mains adapter)

The measuring values are permanantly saved within the device. Of course, the direct logging on the PC as well as the additional readout via Windows software are also possible.

Measuring data can easily be exported as text, Excel or graphic file and futher processed.