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Formaldehyde Multimode Monitor

Innovative new method of Formaldehyde measurement. Formaldehyde is a colorless gas that emits the irritant odor. It is known widely as one of the materials that cause Sick building syndrome. This device brings innovative new method of Formaldehyde measurement.

  • Developed colorimetric sensor element, small size(43×17×4mm), easy to use, reusable, highly accurate and applicable for Passive diffusion sampling.
  • Portable base unit device equipped with photoelectric photometry reading function of absorbance change induced in the sensor.
  • Sensor assy itself can work as stand-alone passive sampler, and it's reusable.
  • Base unit with the sensor inserted can work as on-site monitor for short-term(30min/1h)sampled measurement and continous monitoring for time series variation.
  • This product is not CE marked.
Formaldehyde Multimode Monitor Zoom In

  • About FMM-MD
  • Specification
  • FAQ
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Formaldehyde Multimode Monitor


Example of how the device use

Base unit can be set on the tripod as shown. Sensor assy itself can be used as a sampler. Hang the sensor from a string.

Example for Samplers Measurement.
(Sensor assy with diffusing filter)

Example for Direct or Continuous Measurement.
(Base unit set on tripod stand)


Model FMM-MD
Detection Principle

Photoelectric Absorptiometric

Detection Range 20 - 1,000 ppb
Resolution 1ppb
Concentration Unit ppb or μg/m3
Display Digital LCD
Sampling Method Passive diffusion sampling
Operating Temp. and RH -10 - 40°C (14 - 104°F), 20-90%RH(No dew condensation)
Memory up to 250 sensors and 4500 data
Standard Accessories Sensor Assy x 5 pcs, carrying case,
USB connection cable, Data filing software,
AA size batteries
Option (for replacement)Sensor element (5 pcs/set)

Detection Range

20 to 1,000 ppb. 20 ppb is the lowest reliable value with the stated accuracy, while 10ppb to 20 ppb can be measured and displayed. As the sensor element has absorption breakthrough curve, the highest possible measurable concetration depends of multiplication by concentration and exposure duration. Exposure of 1,000ppb formaldehyde for 30min. is the highest concentration measurement the sensor can do. In the same manner, 24 hours continuous measurement should be done in the condition of lower than concentration of 240ppb.

Light source

415 nm wavelength LED is used as a light source.

Will it affect accuracy if attenuation behavior of light source occurs?

No it won't affect accuracy. Reading function reads the relative difference of the absorbance compared to directly-irradiated reference light intensity all the time.

Effects of humidity

Humidity would affect the sensor, so the another light source with 525 nm wavelength is used to monitor how it is affected, by comparison with direct-irradiated reference light intensity.

Responses for various gases

The sensor react to formaldehyde gas only. Other gases have little effect on the sensor. See the table of Sensitivity to Interference gas. Sensitivity to Interference Gas.

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