Kenwood CS-5140 Instruction Manual

1 1 . FREQUENCY MEASUREMENTSFrequency measurements are made by measuring theperiod of one cycle of waveform and taking the reciprocalof this time value a s the frequency.Procedure:1 . Following the proceudre described in section 5 " T i m eMeasurements", measure the time of each cycle. Thefigure obtained in the signal period.2 . The frequency is the reciprocal of the period measured.Using the formula:Freq - p e r j o c j[EXAMPLE]A period of 4 0 JJLS is observed and measured. (See Fig. 3 3 )Assuming that S W E E P T I M E / D I V indicates 5 ^s/div,substituting the given Value:F r e q = 1 / [ 4 0 x 1 0 " 6] = 2 . 5 x 1 0 4= 2 5 kHzWhile the above method relies on the measurement directlyof the period of one cycle, the frequency may also bemeasured by counting the number of cycles present in agiven time period.1 . Apply the signal to the INPUT jack. Set the verticalMODE to the channel to be used and adjusting thevarious controls for a normal display. Set the V A R I A B L Econtrol to C A L position.[EXAMPLE]For the example, within 7 divisions there are 1 0 cycles.The S W E E P TIME/DIV is 5 /xs/div. (See Fig. 3 4 )Substituting the given value:1 0Freq =7 (div) x 5 (/ts/div)= 2 8 5 . 7 kHzCursor measurement1 . Apply the signal to INPUT jack, setting the verticalMODE switch to the channel to be used and adjustingthe various controls for a normal display.V O L T S / D I V and S W E E P T I M E / D I V to obtain an easilyobserved display.Set the V A R I A B L E to C A L .2 . Set the cursor mode to 1A4T.3 . Adjust the A R E F cursor to the left of the points tobe measured, and the A cursor to the right.4 . Measured value is displayed in the upper part on thescreen posterior to 1 /AT.2. Count the number of cycles of waveform between achosen set of graticules in the vertical axis direction.Using the horizontal distance between the vertical linesused above and the S W E E P T I M E / D I V , the time spanmay be calculated. Multiply the reciprocal of this valueby the number of c y c l e s present in the given time span.If " x 10 M A G " is used multiply this further by 1 0 .Note that errors will occur for displays having only a f e wcycles.26Using the formula:# of c y c l e s x " x 10 M A G " valueFreq=Horizontal distance (div) x S W E E P TIME/DIV settingCount cycles between this portionFig. 3 41 cycle = 4 0 jis (5 /ts/div. x 8 div.)Fig. 3 3