Light Blocker Isokinetic Probes

For applications where sampling is conducted without tubing, Climet offers a light blocking isokinetic probe that fits directly onto the particle counter inlet (i.e., inlet attached). The light blocking ISO Probe is aluminum and hard black anodized, which absorbs stray light. The probe is autoclavable and compatible with IPA and most sanitation fluids.

What is light blocking and why is it important?

Unlike other alternatives, the Climet's wide-scatter sensor is designed to maximize the collection and measurement of light scatter from a  particle. Specifically, compared to other alternatives, there is a significant improvement in the accuracy and stability (or precision) of measurement. The sensor design also contributes to the Climet's particle counter having a significant improvement in mitigating short-term calibration drift. The tradeoff for substantially improved accuracy and precision is that the particle counter is sensitive to fluorescent light and other light fixtures that operate at an on/off frequency of 50Hz to 60Hz. If a particle counter is placed under a fluorescent light fixture without a light blocking probe, the frequency of the fluorescent light ballasts will cause a dramatic and noticeable high rate of false counts. Indeed,  one can expect the lowest channel to show counts well into the millions per cubic meter.

To resolve this issue, Climet uniquely developed the Light Blocking Isokinetic Probe. The  interior is designed with an aerodynamic light blocking element - - What we call the bullet or pitot, which causes the particles to flow around the blocking element, and redirects the particles back into the inlet with no appreciable loss of 5 μm particles. This element is mounted inside the light blocker isokinetic probes, solving the problem of false counts when the instrument is placed directly under a fluorescent light, and, as an isokinetic probe, it helps entrain large particles that should be included in the sample.

Climet has conducted numerous studies dating back to 2011, with additional studies in 2013 and 2015.  Numerous tests were completed, each ranging between 16-25 hours. The particle counts were virtually indistinguishable from the standard stainless steel isokinetic probe, with macroparticle loss of less than 1% variance (Application Note: 20230206A).

Per the above image, Climet offers a range of isokinetic probe that's appropriate for the flow rate of your particle counter.