Keywords
Citation
(2002), "Gemini rheometer", Pigment & Resin Technology, Vol. 31 No. 6. https://doi.org/10.1108/prt.2002.12931fad.005
Publisher
:Emerald Group Publishing Limited
Copyright © 2002, MCB UP Limited
Gemini rheometer
Gemini rheometer
Keywords: Rheology, Torque, Adaptive techniques
Bohlin Instruments has introduced Gemini, which it describes as an advanced rheometer system incorporating a new Rotonetic drive. Gemini is the first Bohlin rheometer featuring Bohlin’s patent pending Rotonetic technology, an adaptive control technology which is optimised for both strain controlled and stress controlled operation.
Key technical features claimed include a broad torque range which extends to 200 mNm and reportedly makes the Gemini suitable for a wide range of applications in research and product development. A new high resolution torque mapping system applied to Bohlin’s inherently low bias air bearing technology allows low torques to be set extremely accurately.
The Gemini system is available with the full range of Bohlin’s EasySwap temperature controllers which include peltier devices, a forced gas oven with optional liquid nitrogen cooling, electrical heating and a range of fluids circulators. This is said to allow the Gemini to be quickly and easily configured to allow testing on a full range of materials and applications including polymer melts, composites, fluids and semi-solids.
The Rotonetic drive enables testing in all conventional strain and stress controlled modes including stress relaxation, creep and viscometric modes. Oscillation testing is available in either direct strain or stress controlled modes. Direct strain operation of oscillation allows preset strain amplitudes to be imposed upon the test sample without iteratively adjusting the stress on a cycle-by- cycle basis. A new feature, partial wave sampling, reportedly enables rheological date to be gathered using just part of a full oscillation cycle. When used in conjunction with direct strain control, partial wave sampling makes low frequency testing for less time consuming and therefore more practical.
Further details are available from Bohlin Instruments Ltd. Tel: +44 (0) 1285 644407; Fax: +44 (0) 1285 644314; E-mail: sales@bohlin.co.uk; Web site: www.bohlin.com