Sampling Accessories: Air Sampling Pumps
While
diffusive sampling offers advantages in terms of cost and simplicity, pumped sampling remains the most versatile option for simultaneous monitoring of multiple target compounds and/or monitoring unknown atmospheres. Given that large air volumes (>100 L) may be drawn through the tubes in many cases, pumped sampling also offers better detection limits than other air monitoring techniques. All
standard and
SafeLok sorbent tubes from Markes International are compatible with pumped tube monitoring.
Constant Pressure Sampling - SKC Sidekick™ Pump
The Sidekick pump has a constant pressure flow range of 5 to 750 mL/min. A special adaptor ensures compatibility with high-impedance sorbent tubes (for example those packed with two or three beds of graphitised carbon black sorbents).
Note that as with all constant pressure pumps, the Sidekick pump will need to be re-calibrated with each individual sorbent tube and before every monitoring exercise.
The pump will operate for 8-9 h on a fully charged battery and weighs less than 600 g. The pump is available in standard and instrinsically safe (ATEX approved) configurations.
Constant Flow Sampling - FLEC® Pump
Constant flow pumps offer the benefit of maintaining sampling flow rates across tubes of varying impedance therefore allowing a range of different sorbent tubes to be used without recalibration of the pump for each tube.
The FLEC pump operates as standard at flow rates from 4 to 1000 ml/min. A special adaptor is available for lower flow rates. (Please contact Markes International directly for more information on this(enquiries@markes.com).
The FLEC pump can comfortably cope with high impedance packings (>1 psi pressure drop at 50 ml/min) because a built-in mass-flow sensor ensures reproducible, precise and constant flows even if the restriction changes dramatically. The FLEC pump is used inside the MTS-32 for sequential sampling onto multiple tubes. It is an ideal complement to SafeLok tubes, both for single tube and sequential sampling.
The FLEC pump is exceptionally stable and there is no necessity to recalibrate it more than once per year unless a significantly different flow rate range is required. The pump may be fitted with optional temperature and % relative humidity sensors. When required, pump calibration (flow, temperature, humidity) is easily carried out using a Windows-based PC program.
The FLEC pump is normally operated via mains electricity making it ideal for indoor air monitoring applications. Rechargeable, 12-hour, battery operation is also available.
For part numbers and pricing please contact your local Markes distributor or visit our eShop
Relevant technical support publications from Markes International can be automatically downloaded from this web site (registration required). Examples include:
Other thermal desorption sampling accessories available from Markes include: