Formaldehyde Multimode Monitor

FM-801 formaldehyde meter is a portable, continuous measurement formaldehyde (HCHO) meter now available from GrayWolf.

A reusable sensor cartridge employs the chemical reaction between formaldehyde and ß-diketone on a porous glass. The yellowing that results from this reaction is measured via photoelectric photometry with accurate readings to <20ppb HCHO, without significant cross-sensitivity from typical background compounds, making it ideal for Indoor Air Quality (IAQ) applications.

Tests run in as little as 30 minutes. The unit ‘re-zeros’ between 30 minute tests allowing for continuous monitoring, and provides an output for real-time connection to most GrayWolf platforms.

  • Continuous monitoring, and/or for 30-minute spot checks.
  • Interface to a GrayWolf AdvancedSense meter, WolfPack monitor or WIN7 Tablet/Notebook.
  • Can a be used as an independent, simple data-logger.
  • Sensor cartridges may also be used as independent passive samplers


Detection Principle Photoelectric Absorpiometric
Detection Range <20ppb to 1,000 ppb,
< 25 μg/m3 to 1230 μg/m3
Accuracy +/- 4ppb <40ppb,
+/- 10% of reading ≥40ppb
Resolution 1ppb
Concentration Units ppb or μg/m3
Display Digital LCD
Sampling Method Passive diffusion sampling
Operating Temp. and RH -10 to 40°C (14 to 104°F), 20 to 90 %RH (non-condensing)
Sensor Shelf Life 1 year from mfg. date (stamped on pouch)
Memory (base unit) up to 250 sensors and 4500 data points
Power Source 2 x AA size Alkaline batteries, or AC adapter
Standard Accessories Sensor cartridge x 5 pcs, carrying case,
USB connection cable, AA size batteries, mini tripod/stand, WolfSense PC data transfer & reporting software




  • Indoor Air Quality monitoring

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