A customer recently brought five environmental studies, ranging from 2013 to 1996, to our attention. Each of the studies details research conducted with one common component: a KNF OEM pump, which proved integral for sample collection or transfer during the analyses. Of the five studies, we cherry-picked two air-toxics studies for your further reading. However, here’s the listing of all five:
- Walter 2013 High Res Measurements Atmospheric Hydrogen West African Coast Mauritania
- Querino 2011 Methane Flux Vertical Gradient Mixing Ratio Measurements in a Tropical Forest
- Bailey 2010 Southwest Indianapolis Air Toxics Study
- Romashkin 2001 In Situ Measurements Long Lived Trace Gases Lower Stratosphere Gas Chromatography
- Elkins 1996 Airborne Gas Chromatography In Situ Measurements Long Lived Species Upper Troposphere Lower Stratosphere
We’re very proud KNF pumps are relied upon within ambient, source and portable devices for environmental sample collection and analysis. For example, the 2010 study listed above details a project in which the Indiana Department of Environmental Management (IDEM), the U.S. EPA, the City of Indianapolis, and a diverse group of stakeholders teamed up to conduct an air toxics study in southwestern Indianapolis, Indiana (this region was identified by the U.S. EPA National Air Toxics Assessment [NATA] in 1996 and 1999 to be an area of potential concern for cancer risk from air toxics).
A KNF pump was used to enable the analysis of the total non-methane organic carbon (TNMOC) concentration of ambient air. For a history lesson, the Clean Air Act Amendments of 1990 required the EPA’s Office of Air Quality Planning and Standards to set National Ambient Air Quality Standard for the “criteria” pollutant, ozone. In areas of the country where the NAAQS for ozone is being exceeded, additional measurements of the ambient nonmethane organic compound (NMOC) concentration are needed to assist the affected States in developing revised ozone control strategies. Measurements of ambient NMOC are important to the control of volatile organic compounds (VOCs) that are precursors to atmospheric ozone.
Therefore, a reliable pump was essential for the collection of air samples with potentially harmful toxics. Simultaneously, it was critical for the pump to collect samples in a manner that didn’t change or contaminate the samples. KNF pumps, known for their reliability and chemical inertness, are ideally situated for this type of application. Additionally, their extremely high gas tightness allows for the accurate and complete collection of media, without the risk of sample loss, dilution, or contamination.
Also, in 2001, a study, titled In Situ Measurements of Long-Lived Trace Gases in the Lower Stratosphere by Gas Chromatography, utilized the KNF NMP 830 pump (referenced as UNMP 830 pump in article) . For this study, a four-channel gas chromatograph measured different air qualities in 70 and 140 second intervals. Air external to the aircraft was delivered to the instrument from an external, variable speed, two-stage, KNF diaphragm pump, driven by a brushless 24-V DC motor. The KNF pump was mounted on the aft wall, and was turned on by the ACATS-IV onboard computer when the ER-2 aircraft ascended through 87 kPa of atmospheric pressure.
Regarding this second study, there are a few points of interest we’d like our readers to note. First, the usage of the pump is a prime example of KNF application flexibility. The KNF NMP 830 micro pump is small; however, its footprint isn’t the only reason it was relied upon within this challenging design. For example, the pump in this application is pulling atmospheric samples at an extremely high altitude, measuring parts per billion (ppb) and parts per trillion (ppt). Expectedly, pump inertness is therefore paramount. Much like in the first study referenced above, environmental analysis customers have come to rely on KNF pump material options, including PTFE and stainless steel, and on the leak tightness of KNF pumps.
Additionally, the KNF pump used in this second study is driven by a brushless DC (BLDC) motor, which helps meet the small size mandate. BLDC allows flow rates to be adjusted as needed, helping to extend the lifecycle and reliability of a device. Motor adjustment is also particularly important for this application, because at high elevations, fewer air molecules are available to blow across the pump for cooling. Therefore, the pump faces the risk of overheating. However, the ability to adjust and operate the motor at a lower voltage and speed helps to mitigate this concern. The small and lightweight design of KNF micro gas pumps even allows for energy-efficient battery operation.
Also of note, there’s far less ambient pressure at the elevation at which the pump in this study is operating, resulting in less pressure on both the top and undersides of the diaphragm. This condition is certainly not ideal for pump operation, which further adds to the difficulty of this application. This, and the other challenges presented by high altitude operation and ppb/ppt detection require a specification-driven, individually-tailored pump. KNF excels in designing and configuring pumps to exacting requirements such as these. In fact, over 80 percent of KNF’s business involves custom-engineered pump solutions.
To round out this review, the first and second studies listed above used KNF pumps to flush sample flasks prior to sampling, and to collect and fill flasks, respectively. The last study used a KNF pump to collect samples in a high altitude study with a set-up similar to the Romashkin 2001 study, which was discussed above.
Summing up this entry to The Pump Post, each of the five studies offers a constant theme of KNF OEM pumps being well-suited for environmental sample collection and analysis applications. Please check back to learn more about KNF products in real-world applications!