the digital multimeter (dmm) precision: good speed: slow points: single recording: pen & pencil
TRANSCRIPT
The digital multimeter (DMM)
precision: good
speed: slow
points: single
recording: pen & pencil
The chart recorder
Figure from Wheeler and Gangi, Introduction to Engineering Experimentation
time
voltage
precision: poor
speed: slow
points: multiple
recording: hard copy
The oscilloscope
time
volta
ge
precision: poor*speed: fast
points: multiple
recording: film*
* A digital oscilloscope can
overcome these limitations
How an oscilloscope works
Figure from Wheeler and Gangi, Introduction to Engineering Experimentation
Precision error reading a ‘scope
Full scale =8 “boxes”
%FS 3.1boxes 8
boxes 0.1 error precision
!
Computer-based data acquisition
precision: good
speed: fast
points: multiple
recording: file
Multi-channel data acquisition system
Figure from Wheeler and Gangi, Introduction to Engineering Experimentation
Computer-based DAQ: signal path
1
2
43
Multiplexer (a.k.a. MUX)
Figure from Wheeler and Gangi, Introduction to Engineering Experimentation
Considerations:
crosstalk
transfer accuracy