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25-lb gauge for oxygen supply and 10-lb gauge for fuel is generally used.

The flow rate of fuel-oxygen mixture usually varies from 2 to 10 cu. ft/h.

An atomizer should have a tip of suitable shape to avoid a strike back.

In flame photometry atoms in vapour state give line spectra and not band spectra.

The usual glass or gelatin absorption filters have wide spectral bandwidths, of 35-45 nm.

Calibration curves are always linear.

In case of high total concentration of solids in the flame the burner may be fouled.

Higher viscosity of sample should be avoided.

If the solution is diluted excessively, errors of dilution may occur and signal to noise ration may decrease.

For an unknown element X in a given sample, it is desirable to know that portable range of concentration of X in the sample.

The element should give spectral lines that are close to those of the analysis element.

The reference element can be added in any concentration to those of analysis element.

The element must be one that is not present in the samples and must be available in a high state of purity.

The reference element must produce radiations that are perfectly selectable.

When added the element must not alter the physical properties of the solution.

Flame background emission

Self-absorption

Direct spectral interference

Effect of ionization

Effect of anions

The source of radiation in IR spectroscopy is ideally a black body radiator.

Globar is a silicon carbide rod.

Nernst filament should be externally heated to dull-red hot.

In Globar water cooling of electrical parts are used to prevent arching.

Nernst filament is operated in parallel with ballast resistance in constant voltage circuit.

Electron spin resonance spectroscopy

Nuclear Magnetic Resonance spectroscopy

Raman spectroscopy

Infrared spectroscopy

Visible spectroscopy

C¹²

N¹⁴

H²

B¹¹

P³¹

Pneumatic detector

GM counter

Bolometer

Pyroelectric detector

Photodiode

ESR sensitivity increases with increasing temperature and decreasing magnetic field.

ESR sensitivity increases with increasing temperature and increasing magnetic field.

ESR sensitivity increases with decreasing temperature and increasing magnetic field.

ESR sensitivity increases with decreasing temperature and decreasing magnetic field.

The sensitivity does not depend on temperature and magnetic field.

The molecule possesses vibrational energy which is associated with transitions of an electron from ground energy level to excited state level.

When the centre of gravity does not change during to and fro motion of nuclei of the molecule, the molecule is said to posses translational energy.

During the motion if the centre of gravity of the molecule changes the molecule which possesses vibrational energy.

Considering an axis perpendicular to the internuclear axis and passing through the centre of gravity of the molecule, then the molecule needs electronic energy to rotate about this axis.

Electronic Energy > Vibrational Energy > Rotational Energy > Translational Energy

Ionisation chamber

Scintillation counter

Semiconductor detectors

Proportional counter

Geiger-Muller counter

C¹⁴

Hg²⁰³

Fe⁵⁹

Zn⁶⁵

Cd¹⁰⁹

PMTs have high internal gain.

The working of PMT is based upon photoelectric effect.

The material of photocathode is usually a mixture of alkali metals

The dynodes are maintained at successively more negative potential.

The response of a PMT is linear.

It defines relationship between Absorbance and Transmittance.

Absorbance is the property of a sample while absorptivity is property of substance.

Radiant energy will diminish in geometric or exponential progression.

This law is true for all types of light.

According to this law if 100% intensity is incident on first layer, then after 4^th year the remaining intensity will be 6.25% (considering equal thickness layers)