Vocab 2

Question 1

Provide simultaneous detection of all the dispersed radiation at the same time in the focal plane of the detector

Answer 1

Multichannel Detectors

Question 2

The ability of a detector to convert radiation to an electrical signal

Answer 2

Responsivity

Question 3

Ratio of electrical output (V) to incident radiant power (W)

Answer 3

Responsivity

Question 4

Radiant energy generates current at interface of a semiconductor and a metal

Answer 4

Photovoltaic cells

Question 5

Incident radiation causes emission of electrons from photosensitive cathode surface

Answer 5

Phototubes

Question 6

Several electrodes separating cathodes and anodes

Answer 6

Dynodes

Question 7

Reverse biased p-n junction formed on SI chip causes holes in depletion layer

Answer 7

Si photodiode

Question 8

Made of semiconductors, acts as light dependent resister

Answer 8

Photoconductivity Detectors

Question 9

Gas heated in enclosed Golay cell cause reaction in thin membrane

Answer 9

Pneumatic cell

Question 10

Detects changes in temp at junction between two dissimilar metals

Answer 10

Thermocouples

Question 11

Resistance thermometer made of semiconductors

Answer 11

Bolometer

Question 12

Insulator with special thermal and electric properties

Answer 12

Pyroelectric

Question 13

Arrays of Si photodiodes placed in integrated circuits

Answer 13

Photodiode array detectors

Question 14

2D array of Si photodiodes

Answer 14

Vidicon

Question 15

Photons strike MOS on P type Si capacitor

Answer 15

Charge couple devices

Question 16

Photons strike Si which generates positive charge

Answer 16

Charge injection devices

Question 17

Energy decay from excited to ground state

Answer 17

Damped oscillating dipole function

Question 18

Lifetime of decay expressed by

Answer 18

Classical damping constant (γ)

Question 19

τ

Answer 19

Excited state lifetime

Question 20

Fourier transformation of an exponentially decreasing amplitude function gives

Answer 20

Lorentzian frequency distribution

Question 21

One cannot measure exactly both the momentum and position of the electron

Answer 21

Heisenberg uncertainty principle

Question 22

The product of the uncertainty in the energy of a state and the uncertainty in the lifetime of that state is approximately = h/2π

Answer 22

2nd Heisenberg uncertainty principle

Question 23

The apparent shift in wavelength of the signal from a source that is moving towards or away from the observer

Answer 23

Doppler effect

Question 24

Convolution of lorentzian and Gaussian

Answer 24

Voigt profile

Question 25

Linear combo of Gaussian and lorentzian profiles

Answer 25

Pseudo-voigt sum functions

Question 26

Product of Gaussian and lorentzian profiles

Answer 26

Pseudo-voigt product functions

Question 27

Strength of signal level relative to the strength of noise level

Answer 27

Signal to noise ratio

Question 28

Lowest [analyte] in sample that can be detected but not necessarily quantified

Answer 28

Limit of detection

Question 29

Lowest [analyte] in sample that can be determined with acceptable precision and accuracy

Answer 29

Limit of quantitation

Question 30

Magnitude and frequency of experimental noise

Answer 30

Noise power spectrum

Question 31

Caused when a finite number of energy carrying particles in an optical device or electrons in electrical circuit; small enough to cause detectable statistical fluctuations

Answer 31

Shot noise

Question 32

Four main types of analog S/N enhancement

Answer 32

Grounding, difference and instrumentation amplifiers, analog filtering, modulation

Question 33

Shielding electrical cables reduces environmental noise

Answer 33

Grounding

Question 34

Compares reference versus sample terminal. Difference between reference and sample signal is amplified

Answer 34

Difference and instrumentation amplifiers

Question 35

Removes high v components, reduces effects of drift and low V noise components

Answer 35

Analog filters

Question 36

Alters some property of carrier wave by a signal so wave encodes signal info

Answer 36

Modulation

Question 37

Electronic amplifier detects particular AC frequency signal

Answer 37

Lock in amplifier

Question 38

Series of discrete, equally spaced windows

Answer 38

Boxcars

Question 39

What can spectral derivatives do?

Answer 39

Enhance resolution; reduce background; discriminate against broad bands; reduce scattering; suppress matrix effects

Question 40

Fraction of radiant power transmitted through cell

Answer 40

Transmittance (T)

Question 41

Optical absorbency is linearly dependent on the solution concentration of the absorbing species

Answer 41

Beers law

Question 42

Radiation scattered outside the normal range of the wavelength selector, and which is passed through monochromater

Answer 42

Stray light

Question 43

The re-emission of radiation at longer wavelengths than the wavelength of initial absorption

Answer 43

Fluorescence

Question 44

Determination of relationship between analyte concentration and analytical response

Answer 44

Calibration

Question 45

Use of chemical reference materials that provide known comparison between concentration and response for calibration purposes

Answer 45

Standardization

Question 46

Reproducibility of results, numerical agreement between replicate measurements

Answer 46

Precision

Question 47

Measure of how close results of analytical measurements come to true value

Answer 47

Accuracy

Question 48

Environment in which your analytical sample exists

Answer 48

Matrix

Question 49

Substance that is added in a known constant amount to all samples, blanks, and calibration standards in an analyte

Answer 49

Internal standard

Question 50

Absolute systematic error, relative systematic error

Answer 50

Bias

Question 51

Blank plus three times standard deviation of blank

Answer 51

Detection limit

Question 52

Ability to discriminate between small differences in concentration

Answer 52

Sensitivity

Question 53

Factors limiting sensitivity

Answer 53

Slope and precision

Question 54

Quantitative definition of sensitivity; slope of calibration curve at concentration range of interest

Answer 54

Calibration sensitivity

Question 55

Concentration that gives a signal significantly different from the background. Lowest concentration where you can reliably distinguish signal from blank

Answer 55

Limit of detection (LOD)

Question 56

Concentration of analyte at which calibration curve departs from linearity by a specified amount

Answer 56

Limit of Linearity (LOL)

Question 57

Useful range of analytical method, extending from LOQ to LOL

Answer 57

Dynamic range