> For the complete documentation index, see [llms.txt](https://docs.aethlabs.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aethlabs.com/microaethalometer-tm-ma600/quick-start-guide/built-in-nafion-dryer.md).

# Built-in Nafion Dryer

The MA600 is available with an optional built-in Nafion dryer for conditioning the aerosol sample in high-humidity environments. Changes in relative humidity can alter the size and optical properties of particles, so drying the sample before measurement improves data quality in humid conditions.

The dryer is a factory-installed option. When ordered, it ships pre-installed inside the MA600 enclosure; there is no customer installation procedure.

It is an active dryer that removes water vapor from the sample through a Nafion membrane, using vacuum together with a counter-flow of dry purge air (reflux mode). The dryer itself is built into the MA600 enclosure, but it is driven by an external purge pump that connects to the rear panel of the instrument.

## Dryer Air Connections

The MA600 rear panel provides two dryer ports:

* **DRYER AIR IN (ATTACH FILTER)** — draws dry purge air into the dryer. An inline filter **must** be attached to this port so that only clean, filtered air is drawn through the dryer.
* **DRYER VACUUM OUT (TO PUMP)** — connects to the external purge pump that pulls purge air through the Nafion dryer.

Attach the filter to the DRYER AIR IN port and connect the external purge pump to the DRYER VACUUM OUT port before operating the dryer.

<figure><img src="https://272274374-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F1fOQ2MnLWcq0ntHW3LLY%2Fuploads%2F9hU15lxejDHgW2J51Hj1%2FMA600allports.jpg?alt=media&amp;token=8a0cc023-fa8a-40a6-b0d6-9ffe2f73a869" alt=""><figcaption></figcaption></figure>

## Powering the Dryer

When the built-in dryer is installed, a second 12V power supply is connected to the external pump in addition to the instrument power. Connect the second M8 sealed circular connector cable of the 12V power adapter to the pump. See [Powering the MA600](/microaethalometer-tm-ma600/quick-start-guide/03-powering-the-ma600.md).

## Dryer Configuration

The dryer purge flow is set using the needle valve on the front panel of the MA600.

<figure><img src="https://272274374-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F1fOQ2MnLWcq0ntHW3LLY%2Fuploads%2Fgit-blob-d83941ea2b113b504621393c1e315d4850a3ee79%2Fma600-needle-valve.jpg?alt=media" alt=""><figcaption></figcaption></figure>