NitroPlex™ Adjust-A-Shelf Desiccator Cabinets

Terra’s NitroPlex™ Desiccator Control System optimizes nitrogen purge efficiency for the most demanding applications, when every second of moisture exposure counts.

The NitroPlex™ is the only humidity control system that combines the monitoring and control capabilities required in zero-tolerance applications with miniaturized semiconductor components, bio/pharmaceutical samples and other moisture-sensitive materials.

Chamber-by-Chamber Multiplexed %RH Monitor/Control

A separate high-accuracy, miniaturized humidity module in each desiccator chamber provides independent monitor/control capability. Each module can be programmed locally or remotely to maintain a humidity set point from ambient down to 0%RH.

Nitrogen is directed only where needed to keep the %RH level below the critical set point.

Cuts System Recovery Time to Seconds

Desiccators controlled by a flowmeter may require an hour or more to regain a humidity set point after a chamber access door is opened. When doors are opened repeatedly, humidity levels can remain above the critical set point for an entire work day.

Testing shows that the NitroPlex™ cuts this recovery time by over 400% in a 4-chamber desiccator (see sidebar below). In Terra's Microccator™ this recovery time is cut to a matter of seconds, eliminating moisture-caused damage.

Product Safety Alarm

The NitroPlex™ eliminates another common cause of moisture exposure: access doors mistakenly left open or ajar. The system directs a high-flow nitrogen purge to any chamber the moment its door is opened. If the door remains opened longer than a specified delay time, the NitroPlex™ issues warning alarms to alert personnel to the problem.

Performance Improvements Spell Big Savings

Costs by over 75%, Improves Efficiency by 400% A desiccator with only one bleed valve may cause more harm than good.

Once an access door is opened, any moisture that enters a cabinet will tend to migrate from one chamber to the next until it exits the cabinet through a bleed valve. In a large, multi-chamber cabinet with only one bleed valve, the moisture may contaminate several chambers.

Even a desiccator equipped with Terra Dual Purge™ and NitroWatch® systems may require 40 minutes or more to purge the moisture and recover the desired humidity set point (see test results at right). In this test, the top chamber of a four-chamber desiccator was exposed to moisture until the humidity level reached 97%RH. Figure 1 (on graph) represents the desiccator efficiency when it was equipped with a single Automatic RB® Valve located in the bottom chamber. The system required 40 minutes to bring the humidity level down to the 10% set point.

If, during that period, another door is opened, this recovery time will be extended further. Very possibly, the cabinet might fail to reach its programmed RH set point over the course of an entire shift, or even longer.

Simply by installing Terra's Automatic RB® (Relief/Bleed) Valve in each desiccator chamber, you can cut both the system recovery time and the nitrogen consumption in half. This is the test case represented by Figure 2 on the graph. Only 20 minutes—and only half as much nitrogen--were required to bring the humidity level to the set point.

The final test case (Figure 3) included a NitroPlex™ control system. With this set up, the desiccator required only 10 minutes to bring the RH from 97% to the set point level of 10%—only a fourth the time required in the first test. It consumed only 15 cubic feet (.42 cubic meters) of nitrogen, only 13% of the amount used in the first test case.

This nitrogen saving alone, nearly 77% in this test, justifies investment in a NitroPlex control system.