BSL PRO Software Guide - Biopac

164 Part DMEASUREMENT Area EXPLANATIONDeltaDelta SDelta T(time)Delta F(frequency)Delta X(arbitrary unit)Minimum area:2 samplesUses:Endpoints ofselected areaMinimum area:1 sampleUses:Endpoints ofselected areaMinimum area:2 samplesUses:Endpoints ofselected areafx i- values of points of a curve ( vertical axis).Results:Returns a dimensionless index that ranges from -1.0 to 1.0 inclusive.Units: NoneSample data file: “ValidateMeasurements.ACQ”Result: -0.74825(for whole wave) and 0.95917 (for first foursample points).Delta returns the difference between the amplitude values at the endpointsof the selected area.Delta f xn f x 1Where:f x 1 , f x n – values of a curve at the endpoints of selected area.Results:If the data value at the starting location is greater than the data value atthe ending location of the cursor, then a negative delta will result.Otherwise, a positive delta will result.Units: VoltsSample data file: “ValidateMeasurements.ACQ”Result: -2 Volts (for whole wave). This result shows the absolutevalue of change of amplitude (2) and the minus sign means a decrease ofamplitude.Delta S returns the difference in sample points between the end andbeginning of the selected area.Results: This calculation will always return a positive result.Units: SamplesThe Delta T/F/X measurement shows the relative distance in horizontalunits between the endpoints of the selected area. Only one of these threeunits will be displayed in the pop-up menu at a given time, as determinedby the horizontal scale settings.Measurement Horizontal AxisDelta T TimeDelta F Frequency (FFT)Delta X Arbitrary units (Histogram Bins)The formula for Delta T/F/X is:Delta T x n x1Where:x1,x n- values of horizontal axis at the endpoints of selected area.Results:If the data value at the starting location is greater than the data value atthe ending location of the cursor, then a negative delta will result.Otherwise, a positive delta will result.For Delta T measurements with the horizontal axis format set toHH:MM:SS.Visit the online support center at www.biopac.com