The Humidity Filtering II Tube dries the sample gas entering pumped instruments. It is particularly suited for removing humidity effects on photoionization detectors (PIDs) while making VOC measurements, and typically lasts for about a half hour of continuous readings.

The Humidity Filtering II Tube utilizes a solid adsorbent to remove moisture without impacting the detection and measurement of most VOCs.



Key Features

	•	Enables continuous reading of VOCs under extremely humid conditions for about one half hour (per tube) at room temperature.
	•	Prevents drifting readings at high humidity when the sensor is dirty. Extends the time needed between sensor cleanings.
	•	Attaches to the Flex-I-Probe inlet with the same adapter used for ppbRAE VOC zeroing tubes.
	•	Especially useful for measuring chlorinated solvents and fuels under high humidity conditions as are often encountered during soil and water remediation.
	•	Can be used with other instruments having a built-in pump such as ppbRAE, UltraRAE, MultiRAE, and VRAE when humidity is an issue, such as PID or low-level LEL sensor measurements. (See TN-178 [below] for adapter connections or for further details.)

* Caution: Absorbs some compounds like ammonia and slows the response of heavy compounds, especially at low concentrations or low temperatures.


Downloads

Humidity Filtering II Data Sheet (695 KB)

Technical Notes

TN-178: Humidity Filtering II Tube for PID Measurements in Humid Environments (245 KB)