**Please Note: The CO2Meter offices will be closed for the Memorial Day Holiday beginning at 5:00PM EDT Friday, May 27, 2022. All operations will reopen Tuesday, May 31 at 8:30AM EDT. Orders placed after 11:00 am et. May 27 will be fulfilled on Tuesday, May 31.**

Hydrophobic Vent Filter Kit

Hydrophobic Vent Filter Kit
Regular price $99.00

POs or wholesale quantity discounts click here

Hydrophobic filters cover the inside vents of all our portable ambient air CO2 meters to allow air flow in while keeping out water droplets, dirt, dust or mold spores that can effect the sensors. This makes our data logger suitable for extreme environment applications like: 

  • In-Situ Incubation
  • Mushroom Growers
  • Caving
  • Fruit and Vegetable Transportation

Easy to install, each kit contains a set of filters for 1 unit. 

CM-0172 Filter Kit used with

  • CM-0016 - 1% CO2 + RH/T Data Logger with Display/Alarm
  • CM-0018 - 1% CO2 + RH/T IAQ Data Logger (AA Batteries)
  • CM-0212 - 1% CO2 + RH/T IAQ Data Logger
  • CM-0213 - 30% CO2 + RH/T Data Logger

CM-0172 kit includes six (6) custom filters.

CM-0173 filter kit used with

  • CM-0039 - 1% CO2 Probe USB Data Logger
  • CM-0040 - 30% CO2 Probe USB Data Logger

CM-0173 kit includes three (3) custom filters.


1.5mm sheets of Porex brand polypropylene (PP) material used to achieve the desired filtering. The filter is rated at 120 to 50 microns. This means that the outside of the filter accepts particles in ambient air up to 120 microns, but the porosity is reduced so that by the time ambient air reaches the inside of the data logger, only particles smaller than 50 microns are passed through.

Effect on Reaction Time

Any material that limits air flow over a diffusion sensor will have some small effect on sensor reaction time. However, we have discovered in testing that the PP material does not slow down the reaction time when the data logger interval is set to 30 seconds or greater. If a higher rate of reaction time is required, you should consider a sample draw data logging meter with built-in pump.

Sensor Filter

In addition to the PP filters, all our NDIR diffusion CO2 sensors have an additional filter on top of the sensor. This filter must remain clean and dry to insure accurate CO2 level readings. If the CO2 sensor filter gets wet, it will no longer accurately read CO2 levels. Under normal conditions, you may be able to simply let this filter dry out to start working again. However, moisture inside the data logger could ruin other components, and will void the warranty.


While the filters should last a lifetime, under the most extreme conditions it is possible that they may become contaminated. As a rule, PP may be used at temperatures ranging from 200 to 300° F (93°C to 149°C). Thus, PP products can be sterilized in an autoclave. You may also send the data logger into CO2Meter.com for filter replacement.

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Customer Reviews

Based on 1 review

Good service

"Easy to install, easy to set up, and easy calibration - just what I was looking for."

- Phillip Farrar
Water Plant Superintendent

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