Lodge stressmeter

There are notable exceptions, however, such as the CEP Lodge Stressmeter . This rheometer is unique in that it measures both viscosity and first normal stress difference, Nl. Both laboratory and in-line configurations are available. The instrument is shown in Figure 4.13. The Lodge Stressmeter is applicable to low-viscosity systems and available commercially from Chemical ElectroPhysics Corp. (Delaware, NJ). 

FIG. 4.13 CEP Lodge Stressmeter. (Courtesy of Chemical ElectroPhysics Corp.)... 

Seismographic Service Corporation, Technical Bulletin on Seiscor-Lodge Stressmeter, Tulsa, Oklahoma, 1978. 

Methods for determining the first normal stress difference at higher shear rates than are accessible using a cone-plate rheometer include the Lodge Stressmeter rheometer [117-119] and the sliding plate rheometer [84]. The former makes use of the pressure measured at the bottom of a small side hole in flow through a slit. It has been demonstrated that these two instruments give comparable results for a polystyrene melt up to shear rates of 200 s" [85]. 

A commercial version of the Lodge Stressmeter is available from Chemical ElectroPhysics (www.cep-corp.com)... 

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