Free CIH Exam Questions That Helps Candidates Pass

p > 0.05 means insufficient evidence to reject the null hypothesis. It does not prove the null true, only lack of evidence. CIHs evaluate statistical and practical significance together.

Dry bubble meters (and piston provers) are primary standards, providing direct volumetric flow calibration. Mass flow controllers (B), rotameters (C), and electronic flowmeters (D) are secondary standards requiring calibration against a primary device. CIHs use primary standards for defensible calibration of sampling pumps.

Ion chromatography quantifies ions by measuring conductivity changes as they elute. Retention time (A) identifies species but not concentration. UV absorbance (C) applies to aromatic compounds. pH (D) is unrelated. CIHs interpret IC results for workplace monitoring of corrosive gases or mists.

Hydrogen sulfide produces a rotten-egg odor detectable at very low concentrations. CO₂ (A) and methane (D) are odorless. Nitric oxide (C) has no strong odor. CIHs confirm with real-time monitoring and odor threshold data.

FID responds to hydrocarbons with high sensitivity, making it standard for solvents. TCD (B) is universal but less sensitive. MS (C) is powerful but costlier. Electrochemical detectors (D) are for specific analytes. CIHs interpret GC-FID data in solvent exposure cases.