FGDS Self Compensation Duct Probe FGDS-SCDP1000



The FGDS Self Compensating Duct Probe (SCDP) has been designed to allow simple, trouble free, representative sampling of duct environments. When used in conjunction with a FGDS ASP1000 or ASP2000 aspirator it provides a complete duct sampling system capable of operating in hazardous areas.

The SCDP draws a representative sample from the whole width of a duct, no matter what the flow rate or pressure in the duct. The design ensures equal volumes of sample are drawn from each duct sampling point, before combining them prior to introduction to an aspirator.

The SCDP operates on the "reverse wing" principle (see Fig 1). The contour of the SCDP creates an area of negative pressure on the opposite side to the airflow direction. The samples are drawn from this area behind the probe protecting the sample holes from becoming blocked by particulate in the duct.

Large particles carried by the flow in the duct, which may block sampling points of traditional probes, will either be too heavy to be drawn into the negative pressure area, or will impact on the face of the SCDP. In either case the SCDP sampling holes will remain unaffected.

Technical Details

Construction - All external surfaces are 316 stainless steel. Internal components are either PTFE or Delryn which are resistant to attack by corrosive gases, Hydrogen Sulphide for example.

If required neoprene sealing gaskets and Delryn isolation sleeves can be provided to isolate the SCDP from the duct wall. Dimensions - Each SCDP is manufactured to fit exactly into a customer’s duct. Maximum length 4m.

For details of the mounting arrangement see fig 2 below:

FIG 1:


FIG 2: