Advanced Isokinetic Sampling

Emission sampling is often carried out under isokinetic conditions. This means that the sampling is performed at the same velocity as the flue gas at the measuring point. For dust measurements, the EN13284-1 standard is applied. For gaseous components such as fluorides and ammonia, specific standards refer to the dust measurement standard for the execution of isokinetic sampling.

Different Methods

Typically, two methods are used for sampling gaseous components: sampling and absorption in the main flow, or in a partial flow. In practice, the latter is most commonly used. This allows for multiple gas samples to be taken simultaneously with the dust sample. Since the late 1980s, Ravebo has been supplying automatic isokinetic samplers. This has resulted in extensive experience and knowledge in application, service, and technical development.

The ST5 Series

The current generation of isokinetic samplers is the ST5 series. The ST5 LT is the most basic model, enabling isokinetic sampling using simple control and minimal components. The ST5 and ST5 Evo are more advanced models with fast control, powerful pumps, and additional features such as heated sampling probes with filter housings. The ST5 Evo features a completely separate pump unit from the control system, requiring only a suction line and electrical cable between the units.

These systems are well-suited for field use thanks to their compact design, lightweight construction, and powerful pumps. All models feature sturdy handles and are finished with rounded corners and rubber bumpers.

Specifications

Behind the pump inlet, there is a high-surface protection filter. In the ST5 and ST5 Evo, there is also a water trap and a sensor to prevent liquid ingress. All systems include full data logging of all measured and calculated parameters. In the ST5 and ST5 Evo, controlled heating of the sampling probe and filter housing is fully integrated, along with storage of temperature data.

Sampling

An automatic leak test can be performed, stored in memory, and included in the measurement report. The automatic isokinetic control can be adjusted to the desired deviation. The partial flow rate for gaseous sampling can be entered and modified during the isokinetic sampling process. The ST5 series is the tool of choice for standardized isokinetic sampling!

All components for sampling are part of Ravebo’s delivery program, including: pitot tubes, sampling probes (heated and unheated), filter holders, goosenecks, nozzles, heated hoses, coolers, gas wash bottles, absorption trains, sampling pumps (constant flow and isokinetic), and more.