Reference
21
Reference
Screen
The MR8875 uses an SVGA (800 x 600) LCD. The waveform dis-
play area uses 625 horizontal dots and 500 vertical dots of the
screen.
The waveform display range is 25 horizontal divisions by 20 ver-
tical divisions, with each frame (division) taking up 25 horizontal
dots and 25 vertical dots on the display. Each data frame (divi-
sion) consists of 100 samples horizontally and 1250LSB vertical-
ly (the exact number varies with the input module). The size of
each data frame (division) varies with the time axis magnification
and compression ratios and the voltage axis magnification and
compression ratios.
25 div
20 div
1 div
Time and sampling
The sampling period is 1/100 of the time axis. When the time axis
range is 100 ms/div, the sampling period is 1 ms. When the time
axis range is set, the sampling period changes accordingly.
Sampling Period
Sampling Points
Measurement
Measurement length setting
The measurement length sets the length (in divisions) to record during each data acquisition event. A recording length
of 1 division consists of 100 data points.
Total data points in recording length = Set recording length (in divisions) 100 data points + 1
Example: For a set recording length of 50 divisions, 50 div x 100 data points + 1 = 5,001 data points
Voltage axis and resolution
The instrument’s resolution varies with the input module. The following table lists the full-scale resolution for each unit.
The maximum resolution can be calculated from the screen’s full-scale value and the full-scale resolution given in the
following table.
Example: For measurements made using the MR8901 Analog Unit
Power supply voltage is measured using a vertical axis of 20 V/div and a vertical zoom of 1x. The maximum resolution
under these conditions is calculated as follows:
Screen full-scale: 1 V/div x 20 div = 20 V
Full-scale resolution for vertical axis of 1x: 25,000
20 / 25,000 = 0.8 mV
Full-scale resolution (LSB) for input modules by vertical axis zoom setting
( ): Indicates the effective data range.
*: The effective range for the MR8902 Voltage/TEMP Unit varies with the thermocouple. For more information about
Input
module
Magnification/compression ratio
×1/10 ×1/5 ×1/2 ×1 ×2 ×5 ×10 ×20 ×50 ×100
MR8901
MR8903
MR8905
250000
(50000)
125000
(50000)
50000 25000 12500 5000 2500 1250 500 250
MR8902* 200000
(40000)
100000
(40000)
40000 20000 10000 4000 2000 1000 400 200
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