Gas Chromatography (Absorption Type) Sample gas moves through a column where the differing sizes of molecules for the individual gases make each gas exit at a different ,
Advantages: Analyzes at once. Very accurate Disadvantages: Requires more than other analyzers. Affected by: and Measures: , , ,
Mass Spectometry Function: Sample is drawn in by vacuum to the chamber. Individual gases are and analyzed. Measures: Gas percentages Advantages: Response time, breath by breath analysis, multiple gas analysis Can analyze: , , , Disadvantages: Expensive, large, high maintenance Most Suitable for: analysis of patient at once rather than individual testing.
CO2/CO/CH4
AKA: Infrared Absorption Analyzer Quick response time is suitable for Calibrate: to room air (%) and known concentration (%) CO then re-zero and use to match read out to concentration. Changes in altitude do affect readings.
Helium analyzer
Also Known as: Conductivity or Bridge Measures: Gas Calibration: To room air (%) and known (%) then use gain to adjust to amount. Do not use with gases. Used with Helium dilution tests.
Nitrogen analyzer
Also known as: Tube Ionizer Sample is pumped into chamber where light is emitted and monitored by a phototube. Intensity of light is directly to N2% Measures gas percentage Capable of breath by breath analysis Calibration: To zero with % O2 and a concentration.
O2 Analyzers Galvanic Cell Analyzer: Measures partial and displays as %. If unable to calibrate you should replace the cell. Calibration during exercise testing: Low -% and high %
Poloragraphic Analyzer Similar to galvanic but uses a Analogous to the electrode Calibration is to % and %
Gas & Water Absorbers CO2 Absorber: AKA Sodium , NaOH (soda or soda-sorb), Baralyme Required for tests (FRC by He Dilution, DLCO-RB) Replace scrubber: When , when changes, or weekly. CO2 Scrubber produce as a by product and should be placed from water absorbers.
Gas & Water Absorbers Water Absorber () Drierite ( Sulfate) Removes moisture as patient breathes through system.
Proper placement of absorbers: 1st: Absorber 2nd: Absrober 3rd: Anaylzer
Permapure (fafion Tubing) Conditions gas to with ambient humidity Allows for accurate correction for humidity in a gas sample.
