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Toxic Gases

The FM-801 formaldehyde meter

HCHO Measurement to very low levels of detection

The FM-801 formaldehyde meters’ measurement range is from 20ppb (parts per billion) to 1ppm (parts per million), with excellent specified accuracy. And the monitor will actually display all the way down to 10ppb (with actual limits of detection below the display value, down to <5ppb). Display your readings in ppb or µg/m3 HCHO. These very low levels of detection are essential for Indoor Air Quality (IAQ) measurement of Formaldehyde, and are typically not achieved by alternative continuous measurement technology.

Formaldehyde Testing; continuous monitoring or spot checks

FM-801 formaldehyde meter is a portable, continuous measurement formaldehyde (HCHO) meter available from GrayWolf. Tests run in as little as 30 minutes. The unit ‘re-zeros’ between 30 minute tests allowing for continuous monitoring/data-logging, and provides an output for real-time connection to most GrayWolf platforms.

Some key facts about this ground-breaking meter:

  • The FM-801 may be used for continuous monitoring, and/or for 30-minute spot checks.
  • The FM-801 can be interfaced to a GrayWolf AdvancedSense meter, WolfPack monitor or WIN7/8 Tablet/Notebook. FM-801 readings are simultaneous to readings from any other sensors connected to the AdvancedSense, WolfPack, Tablet or Laptop, logged into the same data file. Attach audio/photo/video/drawing/text notes to data files for efficient, reliable documentation of environmental surveys.
  • When connected to a GrayWolf meter, readings may optionally be accessed via WiFi, and alerts can be sent via text and e-mail.
  • The FM-801 base unit can also be used as an independent, simple data-logger. Logged data may be downloaded to GrayWolf’s versatile WolfSense PC software (included), and presented in reports generated with GrayWolf’s optional WolfSense ARG automated reporting.
  • Sensor cartridges may also be used as independent passive samplers which are then checked/displayed via the FM-801 Base Unit.

Photoelectric Photometry

A reusable sensor cartridge employs the chemical reaction between formaldehyde and ß-diketone in 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 IAQ applications.


FM-801 interfaced to GrayWolf AdvancedSense Pro
(allows access to powerful AdvancedSense features)

FM-801 Base Unit may be used as a stand-alone display/logger. Sensor cartridges are re-useable.

WIN7 notebook connected to FM-801 (accesses
GrayWolf’s WolfSense LAP enhancements)

Graph formaldehyde trend logs from an FM-801; singly or together with other parameters from any compatible GrayWolf platform


Application Notes

Download “Formaldehyde Testing for IAQ Applications”

Download “USGBC Leed v4 EQc4 – Air Quality Assessment”

Download “The WELL Building Standard v1, for Air Quality Screening”

Download “Asthma Trigger Application Note”

For Detailed Information: