Formaldehyde (HCHO)

Electrochemical Gas Sensor
Solid-state electrochemical gas sensor is now available in WOOFAA Cee, a wireless indoor air quality monitor, as an optional sensor item. This page illustrates the data measuring excellence with this advanced high polymer technology from Germany.
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Solid-state Electrochemical Gas Sensor

Competence Overview

Apart from a compact size, long product life and low cost versus conventional liquid-state electrochemical sensor, our solid-state sensor also has these advantages:

  • Industrial grade precision (accuracy, repeatability & linearity), superior performance above all semiconductive and MEMS type sensors
  • PPB (parts-per-billion) resolution, against to PPM (parts-per-million) on semiconductive and MEMS type sensors
  • Less data drifting over time, no calibration is ever needed over its product life
  • Faster response time, quicker zero recovery, no warm-up time due to its low temperature resistance
  • Immunes towards electromagnetic interference, resulting a lower-cost hardware construction to work with AC power supply and WIFI signals on the same PC board
  • Works well in very dry ambient, as the high polymer file is insensitive to humidity changes
  • Works well in vacuum or anoxic ambient
  • Compact size
  • One-third or one-fourth of price to conventional liquid-state electrochemical type sensors
  • Compliance:
    • RoHS
    • EMC: EN55022 and FCC
    • EU 2002/231/CE Directive
    • EN 13779:2007
    • GB 12358:2006
    • GB 50325:2010
    • GB 3095:1996
    • GB/T 18883:2002
    • TW Indoor Air Quality Standards

Standard Factory Test

Proprietary sensor calibration and baseline adjustment method, appliance and software tools

WOOFAA Cee Offers Configurable Sensor Options as per Your Project Needs

Measures of Formaldehyde

Professional Applications

Model WF2CW-H1T104, measures for new building or renovation work. It covers 5 air quality parameters as:
  1. Formaldehyde upto 1 ppm
  2. TVOC upto 10 ppm
  3. PM2.5 upto 500 µg/m3
  4. Indoor Air temperature
  5. Indoor Relative humidity

Industrial Applications

Model WF2CW-H3000 and WF2CW-H5000, measures in manufacturing plant along production line in proceses involving HCHO emission. They measure 3 air quality parameters as:
  1. Formaldehyde upto 5 or 100 ppm
  2. Indoor Air temperature
  3. Indoor Relative humidity
Linearity Test of gas sensor modules as per standard JJG 1022-2016

Linearity Test

Conducted as per standard JJG 1022-2016 (Verification Regulation of Formaldehyde Gas Detection Instrument) at calibration gas concentrations: 80, 150, 300, 600, 900 ppb.

Typical test result: within ± 15 ppb deviation on all checkpoints.

Gaseous Interference Tests

Gaseous Interference Tests

11 types of span gases are used as a standard method and procedure to quantify interference of our formaldehyde (HCHO) gas sensor.

The noise signals usually fall below 1% of reading. This low level of interference has been out performing many other electrochemical and MEMS types gas sensors.

In fact the MEMS type sensors aiming at low-price gas monitor market seldom has this kind of interference test ever conducted.

Gas Sensor Zero-point Stability Test

Zero-point Stability Test

Conventional semi-conductive and liquid-state electrochemical type sensors are often subjected to data drift even in non-conteminated environment, yeilding shift of baseline and inaccurate measures.

Our solid-state sensors are tested in a contant blow of fresh air for 20 hours, showing a baseline shift < 10 ppb, while the conventional senosrs types often go above 30 ppb.

Gas Sensor Conformance Test

Conformance Test

How a group of sensors measure on a fixed concentration of span gas? This test is to find the answer and to screen out the incompetent.

While any other semiconductive and MEMS types gas sensor fail (deviation greater than 5%), our formaldehyde sensor all fall within 15 ppb in a full-scale measure of 1000 ppb, which is less than 2%.

Gas Sensor Stability Test

Stability Test

How a group of sensors measure over a discontinuous change of concentration? This test is to find the answer and to screen out the incompetent.

While any other semiconductive and MEMS types gas sensor fail (deviation greater than 5%), our formaldehyde sensor all fall within 10 ppb in a full-scale measure of 1000 ppb, which is 1%.

Formaldehyde gas sensor specifications

Formaldehyde Sensor Specifications

Three measuring range options are available for the Formaldehyde gas:

Code  | Range | Resolution
  • X_H1 | 0.01~1 ppm | 1 ppb
  • X_H3 | 0.01~5 ppm | 1 ppb
  • X_H5 | 1~100 ppm | 100 ppb