Week 1; L0, L1, L2, L3 Flashcards
Resolution=
Precision=
Accuracy=
Resolution= the smallest incremental (toegevoegd) quantity that can be measured. When the increment is measured with respect to zero, it is referred to as threshold.
Precision= the smallest difference that the display can show, e.g., depending on the number of digits.
Accuracy= defines the maximum deviation (afwijking) of the measured value from the true value. It’s typically expressed as a percentage of reading or full scale.
Zero drift=
Sensitivity drift=
Zero drift= occurs when the calibration (sensitivity) curve translates in the vertical direction without changing slope or shape. External factors, e.g., temperature variations, are among the major causes.
Sensitivity drift= occurs when the calibration (sensitivity) curve varies its slope or shape, therefore changing the instrument sensitivity.
Low-pass filter=
A low-pass filter is a filter that passes (doorlaat) signals with a frequency lower than a selected cutoff frequency and attenuates (verzwakken) signals with frequencies higher than the cutoff frequency.
Circuit passive elements:
Resistors=
Capacitors=
Inductors=
Resistors= provide resistance, they oppose the flow of electricity, [Ohm].
Capacitor= provide capacitance, they store energy in an electric field, [Farads].
Inductors= provide inductance, they store energy in a magnetic field, [Henry].
Redox reaction:
Oxidation reaction causes atom to lose/gain electrons.
Reduction reaction causes atom to lose/gain electrons.
Redox reaction:
Oxidation reaction causes atom to lose electrons.
Reduction reaction causes atom to gain electrons.
Oxidation reaction is dominant when the current flow is from electrode to electrolyte, reduction dominates when the current flow is in the opposite direction.
Half-cell potential=
Overpotential (Vp)=
Half-cell potential= the potential developed at the electrode of each half cell in an electrochemical cell. It’s determined by: metal involved, concentration of its ion in solution, and temperature.
Overpotential (Vp)= the difference between the observed half-cell potential with current flow & the equilibrium zero-current half-cell potential.
When is a unipolar measurement used and when is a bipolar measurement used?
Unipolar measurement= if measurepoint a is close to a physiologically active membrane and b is relatively far away.
Bipolar measurement= a and b are close to a physiologically active membrane, e.g., when measuring the muscles.
Is an electrode a sensor or transducer?
Both measurand and measurement are electrical potentials, and no power supply is needed to transform the measured quantities (like in a sensor), however… an electrode is a transducer between ionic to electronic current.
Signal conditioning=
Signal conditioning= the manipulation of an analog signal in such a way that it meets the requirements of the next stage for further processing.
Common mode voltage (Vc)= Differential voltage (Vd)=
Common mode voltage= the voltage common to both input terminals of an electrical device.
Differential voltage= a differential voltage is “floating”, meaning that it has no reference to ground. The measurement is taken as the voltage difference between the two wires.
Amplifier=
Operational amplifier (Op-Amp)=
Differential amplifier=
Amplifier= used for interfacing sensors that sense body motions, temperature, and chemical concentrations.
Operational amplifier= (often op amp or op-amp) is a high-gain DC differential amplifier. Characteristics for an ideal op amp:
- Gain (A) is infinite (and constant for all frequencies).
- The CMRR is infinite.
- The input impedance (Rd) is infinite.
- The output impedance (Ro) is 0.
Differential amplifier= a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs.[
Rectifier=
Half wave rectifier=
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation is performed by the inverter.
A half wave rectifier is defined as a type of rectifier that only allows one half-cycle of an AC voltage waveform to pass, blocking the other half-cycle. Half-wave rectifiers are used to convert AC voltage to DC voltage, and only require a single diode to construct.
Wheatstone bridge=
The Wheatstone bridge can be used in various ways to measure electrical resistance:
- For the determination of the absolute value of a resistance by comparison with a known resistance.
- For the determination of relative changes in resistance.
