Spin riffling is the method of choice for sampling accuracy and reliability of the highest order with dry materials. Gilson’s expertise in sampling and analyses of powders and granular material is utilized to produce this next-generation Spinning Riffler. The Gilson Spinning Riffler features a custom designed touch-screen controller/display, minimal moving parts and an outer case designed for easy clean-up and maintenance. Operation is quieter and safer thanks to an isolated motor and vibrator, automatic belt-drive system and sample vessel enclosure. Both rotation speed and vibration level are displayed on and precisely controlled from the touch screen.
The Gilson Spinning Riffler virtually eliminates operator error and the bias associated with other types of sample dividing. The accuracy of spin riffling has been demonstrated in the 1968 M.Sc. thesis of A. A. Khan, Bradford University. Sampling tests based on a 60/40% mixture of coarse and fine sands produced the following comparisons:
The Spinning Riffler uses a vibratory feeder trough to provide a constant flow of material from a stainless steel hopper with approximately 1L capacity. A dividing head constructed of durable urethane-based resin sharply separates the flowing material into as many as sixteen glass sample vessels, each about 60ml in volume. Standard Tube vessels may be used, or vials with screw-top caps in different sizes of amber or clear glass are available. The vials enable freshly divided samples to be capped and stored immediately, with minimal handling and little chance for outside contamination. Either type of sample vessel is contained within the sample drum during operation to minimize exposure of moving parts and contain any spillage. Retention of 1-16 representative samples of 1/16 of total sample capacity each is accomplished simply by leaving tubes or vials out of the sample drum. Excess material will then flow directly into the sample drum. Rotation speed is continuously variable between 0-20rpm and the vibration amplitude of the feeder is variable as well. All adjustments are controlled and displayed on the touch screen. The drive system consists of a unique, digitally controlled stepper motor turning a toothed belt and cogged drive wheel. Speed control is very accurate with no slippage under normal loads. If an accidental overload or blockage occurs, the system will slip to prevent damage to the motor. A separate motor operates the vibratory feed system at 60Hz frequency and digitally controlled variable amplitude. A “sleep” mode conserves power when the unit is not operating. Power for the unit is supplied through a standard IEC input receptacle. Main supply voltage is automatically sensed, allowing any AC input from 85-264V, and 47-63Hz single phase. A power cord is supplied for use with standard North-American outlet configurations. Power cords for other configurations are readily available locally.
The Gilson Spinning Riffler includes a sixteen-port Dividing Head, a set of sixteen Standard Tube Sample Vessels, a Sample Drum to contain the vessels and a Holder Plate for positioning the vessels in the drum. All are listed below as separate accessories for more efficient sample processing or as replacements. Glass Sample Vials with threaded tops and included caps are also available.
Dimensions with Hopper in place: 13x20.5x23in (330x521x584mm), WxDxH.