Which detector provides the measurement for Volatile Organic Compounds in ambient air with this device?

• A. Low energy sensor
• B. Flame ionization detector
• C. Mass spectrometer
• D. Photo Ionization Detector

Answer: (D)

Photo Ionization Detector is the best fit here because it uses ultraviolet light to ionize most volatile organic compounds in the air and then measures the resulting ion current. This gives a fast, real-time reading of VOC presence and concentration across a broad range of compounds without needing reagents or complex sample preparation, which is ideal for ambient air monitoring with a portable device.

Other detectors have more specialized or bulky uses: flame ionization detectors require a flame and are typically paired with gas chromatography to analyze separated compounds, making them less practical for straightforward ambient air monitoring. Mass spectrometers offer detailed identification and extremely high sensitivity but are large, expensive, and require vacuum systems and complex data analysis, not suited for a simple ambient air detector. A low energy sensor is not a standard, reliable method for broad VOC measurement in ambient air, so it wouldn’t provide the same comprehensive readout.