Programming instructions

Chapter 18 Things You Should Know about SCXI
LabVIEW Data Acquisition Basics Manual 18-2
© National Instruments Corporation
To measure signals from transducers, you must convert them into a form
that a data acquisition (DAQ) device can accept. For example, the output
voltage of most thermocouples is very small and susceptible to noise.
Therefore, you may need to amplify and/or filter the thermocouple output
before digitizing it. The manipulation of signals to prepare them for
digitizing is called
signal conditioning
. The following are some common
types of signal conditioning.
• Amplification
• Isolation
• Filtering
• Transducer excitation
• Linearization
Figure 18-1 shows some common types of transducers/signals and the
required signal conditioning for each.
Position
(displacement)
Potentiometers
Linear voltage differential transformer
(LVDT)
Optical encoder
Fluid flow Head meters
Rotational flowmeters
Ultrasonic flowmeters
pH pH electrodes
Table 18-1.
Phenomena and Transducers (Continued)
Phenomena Transducer