Spectrum Mobile Spider Wheel

The Spectrum Mobile Spider wheel is designed to take the concept of a spider wheel and make it mobile. So that the same chute with spider wheel can be moved between different processing equipment. For example used to monitor the output of a batch granulator, but moved to monitor the next step of drying, then moved again to monitor the output of a mill. The device will integrate standard NIR, UV, Raman and Particle size analyser probes into moving powder streams, by connecting the ends of the fixed chute into the material stream. The chute can be moved to different angles, slopes and heights. The spider wheel can be swapped out to accommodate different materials from different process. The dedicated chute houses a rotating wheel with various shapes of fingers, that rotate within the powder stream, capturing powder over the probe window mounted below the spider wheel.

The fingers are designed to systematically control collection of a sample from a moving powder bed such that a good PAT measurement may be made.

The fingers of the spider wheel are designed to capture an optimal amount of sample to be scanned over the window of a probe, then move that sample onwards down the chute or pipe, at the same time, wipe the probe window ensuring fresh sample replaces the scanned material over the probe.

The underside of fingers of the spider wheel are lined with a PTFE layer, which eliminates the light reflected off the bare metal of the fingers, which would otherwise add significant noise the the spectra collected by the spectrometer probe.

There are a range of sizes of the spider wheel depending on required flow rates of the sample stream.

The spider wheel base can be heated to reduce the possibility of material sticking to probe window or the device itself.

The device is constructed from fully traceable and certified FDA approved materials of construction. Air actuation of the device allows safe use of the Spectrum Probe Holder in ATEX Zone 21/22 process environment.


  • Zone 21/22 process environments
  • Pressure rating: 10Bar max.
  • Contact materials: 316L stainless Steel, highly polished
  • Diameter range of probes that can be accommodated 12- 32mm
  • Probe lengths between 200 – 300mm can be accommodated
  • The spider wheel base can have has internal heating in the range ambient to 80 degrees C


  • This spider wheel is particularly good for powder streams moving down a chute or pipe
  • Material exiting equipment like a mixer, granulator or mill
  • The interface can be used with continuous processes or when off-loading batch processes