Measurement Uncertainties; Random Uncertainties; Systematic Uncertainties - Fluke PM6690 Operator's Manual

Repetitive
Sampling: Up to 100 Msa/s equiv.
sample rate (10 ns be-
tween samples)
Continuous
Single Period: Yes, from LF to 0.5 MHz
repetition rate
Waveform
Capture: Yes
Data Analysis
Features: Measurement data vs
time
FFT graph w. Hamming,
Hanning and other rele-
vant filters
Root Allan variance
Smoothing
Zoom
Cursor measurements
Distribution histogram
Setup, measurement data
archive and printing
Measurement
Uncertainties

Random Uncertainties

n
Quantization Error (E
E
n
Start/Stop Trigger Error (E
-
( Vnoise input
=
E ss
Signal slew rate
200 mV
V :
noise-input
noise
V : The rms noise of the
noise-signal
applied signal
)
q
= 100 ps rms
q
ss
2 2
+ -
) ( Vnoise signal )
V
( s at trigger point )
typical internal
rms

Systematic Uncertainties

n
Trigger Level Timing Error (E
Time Interval, Rise/Fall Time, Pulse Width,
Duty Factor (x1)
E = TLU x (1/Sx + 1/Sy) ± 0.5 x Hyst x (1/Sx
tl
[s]
+1/Sy)
where:
Sx = Slew rate at start trigger point (V/s)
Sy = Slew rate at stop trigger point (V/s)
TLU = Trigger level uncertainty (V)
Hyst = Hysteresis window (V); Hyst = 5 mV
± 1 % of set trigger level (DC to1 kHz)
Phase with sinusoidal signals and trigger
levels = 0 V (x1)
E = 0.001/V
tl
where:
V = Input A peak voltage in V
pk (A)
V = Input B peak voltage in V
pk (B)
n
Display Resolution
LSD Displayed
Unit value of the least significant digit dis-
played. All calculated LSDs should be
rounded to the nearest decade (e.g. 0.3 Hz is
rounded to 0.1 Hz, 5 Hz is rounded to 10 Hz)
and cannot exceed the 14th digit.
Frequency & Period
(
=
LSD
displ
)
Resolution in s.
s rms
Time Interval, Rise/Fall Time,
Pulse Width & Ratio
= Resolution / 2
LSD
displ
Duty Factor
= ´
LSD
1 10
displ

Measurement Uncertainties 8-9

Specifications
[°]
+ 0.001/V
pk (A) pk (B)
´
Resolution / ) 2 Measurement Result
Measuring Time
-
6
)
tl