FinePointe WBP and Inhalation Tower systems may include Temperature/Humidity probes that are used to measure those values in the air exposed to the subjects.  These probes can drift over time when exposed to VOCs (Volatile Organic Compounds) in the air. 

To assess this possible drift, an additional Temperature/Humidity probe is included with each of these systems.  This Reference Probe is identified by a red cable and should remain in its closed static-protected bag to isolate it from airborne VOCs, thereby mitigating possible sensor drift.  The intent of this Reference probe is that the customer can routinely connect it to their system and compare its values to those from the other probes. 

If a Temperature/Humidity probe is found to have drifted by a significant amount, the customer can then request a Warranty replacement or purchase a replacement if older than 1 year.