CIH Exam ACTUAL QUESTIONS AND
CORRECT ANSWERS
Mist/Fog particle size - CORRECT ANSWER 5-100 um
Smoke particle size - CORRECT ANSWER less than 1 um
Fume particle size - CORRECT ANSWER less than 1 um (tend to agglomerate into
clusters)
Breathing Zone - CORRECT ANSWER NEW - hemisphere forward of sholders with a
radius of 6-9"
OLD - 2' diameter sphere centered on head
Systematic Error - CORRECT ANSWER Correctable error - malfunction of sampler,
instrument, or operator - affects accurancy (not precision)
Random Error - CORRECT ANSWER Unknown/uncontrollable error - random
fluctuations of equipment/procedure - affects precision
Activated Charcoal - CORRECT ANSWER organic vapors
Silica Gel - CORRECT ANSWER polar and high-boiling organics/inorganics
Porous Polymers (XAD, Tenax) - CORRECT ANSWER organic vapors
Molecular Sieves, Alumina Gel - CORRECT ANSWER polar vapors
Adsorption - CORRECT ANSWER one substance just hangs onto the outside of
another. Think of people holding onto a car trolley with one hand and leaning off the side
, Absorption - CORRECT ANSWER one substance enters completely into another.
Think of people walking into and sitting down in a car trolley.
Solvent Desorption Efficiency (NIOSH) - CORRECT ANSWER greater than 75%
Spectrophotometers - CORRECT ANSWER IR - MIRAN, simple organic vapor
mixtures, FTIR
UV - Hg detetor
Vis - Halide meter (halogen compounds)
Ionization Detectors - CORRECT ANSWER FID - (flame) general hydrocarbon
PID - (photo) sensitive for aromatic HC, 9-12 eV
Catalytic Combustion - CORRECT ANSWER LEL meter - heated wire - percent level
detection - needs O2
Electrochemical Cells - CORRECT ANSWER good for reactive inorganics (O2, O3,
NOx, SO2, CO)
Flame Photometric Detectors - CORRECT ANSWER good for sulfur containing
compounds
Gas Chromatography - CORRECT ANSWER uses various detectors - FID, PID, FPD,
ECD (electron capture - chlorinated or brominated organics)
Nitrous Oxide - CORRECT ANSWER Tedlar Bag, Portable IR
Benzene - CORRECT ANSWER Tedlar bag, GC-PID
CORRECT ANSWERS
Mist/Fog particle size - CORRECT ANSWER 5-100 um
Smoke particle size - CORRECT ANSWER less than 1 um
Fume particle size - CORRECT ANSWER less than 1 um (tend to agglomerate into
clusters)
Breathing Zone - CORRECT ANSWER NEW - hemisphere forward of sholders with a
radius of 6-9"
OLD - 2' diameter sphere centered on head
Systematic Error - CORRECT ANSWER Correctable error - malfunction of sampler,
instrument, or operator - affects accurancy (not precision)
Random Error - CORRECT ANSWER Unknown/uncontrollable error - random
fluctuations of equipment/procedure - affects precision
Activated Charcoal - CORRECT ANSWER organic vapors
Silica Gel - CORRECT ANSWER polar and high-boiling organics/inorganics
Porous Polymers (XAD, Tenax) - CORRECT ANSWER organic vapors
Molecular Sieves, Alumina Gel - CORRECT ANSWER polar vapors
Adsorption - CORRECT ANSWER one substance just hangs onto the outside of
another. Think of people holding onto a car trolley with one hand and leaning off the side
, Absorption - CORRECT ANSWER one substance enters completely into another.
Think of people walking into and sitting down in a car trolley.
Solvent Desorption Efficiency (NIOSH) - CORRECT ANSWER greater than 75%
Spectrophotometers - CORRECT ANSWER IR - MIRAN, simple organic vapor
mixtures, FTIR
UV - Hg detetor
Vis - Halide meter (halogen compounds)
Ionization Detectors - CORRECT ANSWER FID - (flame) general hydrocarbon
PID - (photo) sensitive for aromatic HC, 9-12 eV
Catalytic Combustion - CORRECT ANSWER LEL meter - heated wire - percent level
detection - needs O2
Electrochemical Cells - CORRECT ANSWER good for reactive inorganics (O2, O3,
NOx, SO2, CO)
Flame Photometric Detectors - CORRECT ANSWER good for sulfur containing
compounds
Gas Chromatography - CORRECT ANSWER uses various detectors - FID, PID, FPD,
ECD (electron capture - chlorinated or brominated organics)
Nitrous Oxide - CORRECT ANSWER Tedlar Bag, Portable IR
Benzene - CORRECT ANSWER Tedlar bag, GC-PID
