1. Measurement Hardware Sensor: Transducer: Signal Conditioner:
Signal Processor:

2. Sensors and Transducers

3. A Simple Measurement System
liquid
stem
bulb
scale
Sensor:
Transducer:
Signal Conditioner:
Signal Processor:

4. Some Sensors hot-film probe (or RTD) R=Ro[1+a(T-To)] thermistor
R=Roexp[h(1/T-1/To)]
strain gage
(R=rL/A)

5. LEX-2 Pressure Transducers

6. LEX-2 Pressure Transducers

7. Amplifiers
amplifiers

8. Amplifiers An amplifier is an electronic component that scales
the magnitude of a signal from its input value, Ei,
to its output value, Eo.
Functionally, this can be expressed as Eo = f[Ei],
where f is some amplification operator.
For a linear amplifier, Eo = , where G is the gain.
For a logarithmic amplifier, Eo =

9. Figure 6.4: The LM124 Series Op Amp
Operational Amplifiers
Figure 6.4: The LM124 Series Op Amp

10. Operational Amplifiers
The complex circuit of the op amp can be modeled
as a ‘black box’ having two voltage inputs and one
voltage output.
Figure 6.5
It major attributes are:
[1]
[2]
[3]

11. Figure 6.7

12. Differential Op Amp Equation
Kirchoff’s First Law can be applied to determine the amplification
factor for this configuration. B
at node B,
at node A, A
Now EA = EB because the voltage difference between the inputs is
zero (a consequence of the op amp’s high internal open-loop gain).
Equating the two expressions yields the desired factor.