Linear dynamic range , 245 defined

Thus the slope of the Log/Log curve will give the value of the response index (r). If the detector is truly linear, r = 1 i.e. the slope of the curve will be sin 7r/4 =1). Alternatively, if suitable software is available, the data can be curved fitted to a power function and the value of (r) extracted from the results. The same data can be employed to determine the linear range as defined by the ASTM E19 committee. In this case, however, a linear plot of detector output against solute concentration at the peak maximum should be used and the point where the line deviates from 45° by 5% determines the limit of the linear dynamic range. 

Linear Dynamic Range - (D ) - The linear dynamic range of a detector is that concentration range over which the detector response is linear within defined response index limits. It is also dimensionless and is taken as the ratio of the concentration at which the response index falls outside its defined limits, to the minimum detectable concentration or sensitivity. The linear dynamic range is important when the components of a mixture being analyzed cover a wide concentration range. 

This again emphasizes the need for an improved procedure for defining detector specifications. The linear dynamic range of the electron capture detector is again ill-defined by many manufacturers. In the DC mode the linear dynamic range is usually relatively small, perhaps two orders of magnitude, with the response index lying... 

The linear dynamic range (DJ of a detector is that range of solute concentration over which the numerical value of the response index falls within defined limits. For example, the linear dynamic range of a detector such as the FID might be specified as... 

The preparation and execution should follow a validation protocol, in which the scope of the method and its validation criteria should first be defined (46). The scope of the analytical method should be clearly understood since this will govern the validation characteristics that need to be evaluated. For example, if the method is to be used for qualitative trace residue analysis, there is no need to examine and validate its linearity over the full dynamic range of the equipment. The scope of the method should also include the different types of equipment and the locations where the method will be run. In this way, experiments can be limited to what is really necessary. For example, if the method is intended for use in one specific laboratory, there is no need to include other laboratories and different equipment in the validation experiments. 

The linear range of an analytical method is the analyte concentration range over which response is proportional to concentration. A related quantity defined in Figure 4-12 is dynamic range—the concentration range over which there is a measurable response to analyte, even if the response is not linear. 

Dynamic range is defined as the range of either ion counts a linear response is obtained. 

Creep-compliance studies conducted in the linear viscoelastic range also provide valuable information on the viscoelastic behavior of foods (Sherman, 1970 Rao, 1992). The existence of linear viscoelastic range may also be determined from torque-sweep dynamic rheological experiments. The creep-compliance curves obtained at all values of applied stresses in linear viscoelastic range should superimpose on each other. In a creep experiment, an undeformed sample is suddenly subjected to a constant shearing stress, Oc. As shown in Figure 3 1, the strain (y) will increase with time and approach a steady state where the strain rate is constant. The data are analyzed in terms of creep-compliance, defined by the relation ... 

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