• NitroPlex system provides chamber-by-chamber humidity control using individual RH sensors
• Built-in plenum distributes high-flow nitrogen to each chamber on-demand
• Multi-chamber cabinets isolate different types of stored materials
• Reduced impact on other chambers when one door opens
• Stainless steel racks installed in each chamber; shelves adjust in 1" increments
• Chrome-plated, ergonomic LiftLatches™ do not scrape the chamber like ordinary rotary latches
• Stainless steel-framed doors extend service life and provide a better door seal
• Mechanically attached, one-piece gasket does not creep or crack
• Automatic RB® Valves release moisture-laden air from the cabinet and prevent over-pressurization
• Electrical grounding available; specify when ordering (included standard on Static-Dissipative PVC models)
• Includes one NitroPlex Humidity Module per chamber, one automatic relief/bleed valve per chamber, and one perforated stainless steel shelf (order additional shelves separately)
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.
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.
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.
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.
NitroPlex™ Cuts N2 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.
The standard NitroPlex™ system provides unsurpassed moisture control in dozens of storage applications. Temperature, gas or biological sensors expand the range of critical operations.
Which critical control application can you find in your facility?
Desiccators must be continuously purged with nitrogen or another process gas in order to ensure a controlled environment free of contaminants and moisture.
Unfortunately, however, a steady gas inflow can't guarantee the clean, dry conditions you require. A flow adequate to maintain a safe internal positive pressure when doors are closed is insufficient to overcome the backflow of outside air that occurs when a door is opened. A higher-level purge that might guard against this backflow wastes nitrogen and leads to over-pressurization that warp doors and damage seals.
The Desiccator Dual Purge System solves these problems by providing a higher flow level only when it's needed, and only for as long as it's needed.
It relies on a sensor switch installed on each door. During normal operation, with all doors closed, the system maintains an economical low flow of nitrogen into the desiccator to ensure a constant positive pressure of about 0.05" WG (Water Gauge)—just enough to block out moisture and contaminants.
When a door is opened, the sensor switch immediately activates a high-flow purge of nitrogen into the desiccator's plenum chamber that minimizes the influx of moisture and contaminants.
When the door is closed, the high-level gas flow continues to purge the desiccator for a selectable period of time, ensuring that any moisture that does enter the chamber is quickly forced out of the Automatic RB® (Relief/Bleed) Valve, before it can degrade sensitive materials. This time delay is adjustable, so you can retain the high-flow for a longer time when you suspect moisture contamination may have occurred. Note: The Automatic RB® Valve must be ordered separately.
The dual-purge capabilities of these units ensure that contaminants and moisture stay outside the processing chamber and at the same time guard against dangerous over-pressurization that can lead to warped doors, failed seals—even explosions! And because the Dual Purge System delivers only as much gas as is necessary, it economizes on nitrogen consumption; tests show that in many applications, these units can pay for themselves in a matter of months.
The Dual Purge System incorporates a flowmeter, a line pressure gauge and a variable purge mechanism. A “Low-Pressure” alarm is activated if the incoming line pressure is ever interrupted. This dual audible/visible alarm alerts you to a disconnected supply line, an empty gas storage pod, or other problem that could spell disaster for contents of a desiccator or glove box!
The Dual Purge System operates in tandem with Terra's NitroWatch System to fully automate moisture control.
The NitroWatch includes a humidity sensor that continuously monitors the internal RH level and activates the Dual Purge to automatically maintain any sub-ambient humidity threshold you require (down to 0% RH). For more critical requirements, select the NitroPlex™, which combines this automatic humidity control with multiplexed purge capability. In all of these applications, the Automatic RB Valve is required to ensure safe relief of over-pressurization that can build inside a chamber.