FAQ - SITA CleanoSpector
Which contamination does the SITA CleanoSpector detect?
The SITA CleanoSpector detects fluorescent organic residual contamination on parts' surfaces such as oils, greases, cooling lubricants, waxes, corrosion protective coats, and cleaners as well as flux material or solder resist lacquers. The SITA CleanoSpector can also detect non-fluorescent materials when fluorescence marker are added.
Are the test results of the SITA CleanoSpector comparable to the results of test inks?
The test results of the SITA CleanoSpector are only partially comparable to the results of test inks.
The SITA CleanoSpector detects organic contamination on surfaces. Test inks can only examine the surface regarding to its wetting tension or surface energy. Contamination can have different surface energy. If there are remaining residuals or wetting agents on the surface the results with test inks are falsified.
Is the UV radiation dangerous for the user of the device?
No, the outcoming radiation from the ray-opening isn't dangerous for the user if the device is properly used for its defined purpose. Nevertheless, you can not look directly into the ray-opening while measuring.
What influence does the measuring distance have on the test results?
An increase of the measuring distance causes an increase of the excited surface and a decrease of the intensity of excitation radiation per surface. Furthermore, the part of the detected fluorescence radiation decreases as well because it is emitted diffusely in all directions. For this reason the intensity of the measured fluorescence decreses and the output cleanliness rises. A decrease of the measuring distance causes an increase of detected fluorescence radiation so the output cleanliness decreases.
The measuring distance (front sensor surface - parts' surface) should amount to 4.7 mm +/- 0.2 mm. If a spacer is used you should position them on the surface.
Why does the SITA CleanoSpector have to be calibrated?
In order to evaluate surfaces regarding their cleanliness in % the SITA CleanoSpector has to be calibrated on an absolutely clean surface.
When calibrating you measure the basic value of a clean surface in RFU. For the subsequent measurements with the respectively choosen measurement profile (type Cleanliness) the test results are determined from the measured RFU reading.
Note: Contamination on the lense can fluoresce or absorb light respectively so that the sensitivity of the device will decrease with regard to detecting the slightest contamination.
For the adjustment of the fluorescence sensors for the correct output of the RFU measuring value, SITA provides the user with working standards.
How do I prepare a calibration surface?
After cleaning the calibration surface it should be completly clean and it should be free from residues of fluorescent materials. In most cases an intensive cleaning using the cleaning agents from the process or a solvent such as a silicone remover and IPA is applicable. Afterwards the surface has to be rinsed with DI-water completely and dried by clean air.
If the samples are not properly prepared the sensitivity of the device with regard to detecting the slightest contamination decreases.
How many calibration surfaces can be saved within the SITA CleanoSpector?
SITA CleanoSpector can save different calibrations in 255 measurement profiles.
Is it necessary that the sensor head has to be positioned vertically to the surface when realizing a contact free measerment?
While measuring the sensor head should be positioned approx. vertically to the surface. Although, deviations of 20° can be neglected. If the sensor head is held in an stronger incline position, the surface that is stimulated by the excitation ray will increase and the intensity of the excitation radiation per surface will decrease. Thus, the RFU output value decreases (or % cleanliness rises).
Which influence has the ambient light?
The SITA CleanoSpector is able to automatically compensate the ambient light. Thus, the ambient light doesn't have any influence on the measuring results.
During measuements direct solar radiation has to be avoided, because it can lead to an overload of the detector diode. Rapid changes of the lighting conditions, for example switching on the ceiling light while measuring might cause measuring deviations. In order to decrease those accidential measuring deviations the SITA CleanoSpector is equipped with a median filter.