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NitroWatch System
For operation with Terra's Dual Purge™ System


continuous flow intermittent flow gal bleen through RB valve
Continuous low flow Intermittent high flow Gas bleed through RB valves
internal humidity monitor purge control
Internal humidity monitor
Purge control
NitroWatch: Humidity Monitor & Control (Dual Purge System, RB valve required)

CE Mark All desiccator cabinets and Dual Purge/
NitroWatch control systems.
CE Declaration
  • Automatically controls Dual Purge System to maintain the desired low relative humidity level (2%RH to ambient) in a desiccator or other enclosure
  • Reduces nitrogen costs by up to 78%
  • Continuously monitors and displays relative humidity level
  • Automatically compensates for shifting environmental variables, eliminating guesswork and reliance on supervisory personnel
  • New miniaturized sensor eliminates dead space inside glove boxes
  • Easy-program control functions

Purging a cabinet with nitrogen is an effective way to maintain a low-humidity storage environment. Using a flowmeter to control the nitrogen purge gas, however, leads to unnecessary expenses!

If you set the gas flow level too high, expensive nitrogen is wasted and cabinet seals are exposed to excessive pressure that could lead to leaks (or even ruptures!). If you set the flow level too low, you may wind up with ineffective contamination and moisture control and expensive component damage. Both problems have cost the semiconductor industry millions of dollars annually.

Terra Universal's NitroWatch solves these problems by sensing and displaying the relative humidity of an enclosed environment, such as a desiccator, Faraccator™, or glove box. More importantly, it operates with the Dual Purge System to precisely control the flow of nitrogen into the enclosure and maintain a preset humidity level.

Operation is simple and reliable. Simply program the desired level, and then let the system do its job. The fast-response, capacitive-type sensor detects the relative humidity; the level is indicated on a 4-digit LED display. The NitroWatch controls Dual Purge System operation to maintain the setpoint level—no matter how often doors are opened, or how large the system is, or what the ambient humidity is, or what time of the day or night. High-flow purges are initiated only when a door is opened or the humidity climbs above the set-point. The moment acceptable conditions are restored, the system returns to low-flow purging.

Cuts Nitrogen Waste for Additional Savings!
Higher quality control and reduced part rejects are two convincing reasons to consider the NitroWatch. But they aren't the only ones.

Your biggest savings will probably come in reduced nitrogen expenses. Typically, the nitrogen flow in a desiccator cabinet is set at a level high enough to compensate for access to stored parts during working hours; this means that a constant high-level purge is required. Yet in most cases, doors remained closed for over 75% of the time!

During off hours, weekends and holidays, unnecessarily high amounts of nitrogen are fed through the system and bled out as waste—even though no flow (or only a very minute flow) may be needed to maintain the appropriate internal humidity and positive pressure. Excess nitrogen bleeding can even endanger worker safety if ambient oxygen levels fall too low.

When you turn out the lights and lock the door, the NitroWatch will cut out the nitrogen waste. This savings alone in most cases pays for the system within six months. Test data show typical savings of 78% of nitrogen consumption. And you'll be assured that stored components (and your workers) are safe.

Space-Saving Sensor
The NitroWatch sensor is installed in the bottom desiccator chamber without interfering with shelves, doors, process equipment, or stored materials. This sensor features miniaturized components that provide better than 2%RH accuracy over the 10%-90%RH range. Further, it never requires calibration.

The NitroWatch controller comes complete with all necessary controls for monitoring the relative humidity level. For automatic humidity control, the unit must be connected to Terra's Dual Purge System. Order the NitroWatch Sensor separately (see below).

Dimensions: 11"W x 6.5"D x 3"H (279 mm x 165 mm x 76 mm)
Weight: 4 lbs., 7 ozs. (2010 g.)
Power: 12 VDC (provided by Dual Purge™ System)
Case Material: 304 Stainless Steel
Output: 0-5 V
Measuring Range: 0-100%RH
Display Resolution: ±.1%RH
Temperature Dependence: ±0.04%RH/°C
Dimensions: 1.5" x 0.75" x 4" (38 mm x 19 mm x 102 mm)
Weight: 3 ozs. (85 g.)
Measuring Range: 0-100%RH
Accuracy (at 20°C): ± 2%RH
Housing Material: 304 stainless steel
Calibration: None required
Click any price to add to cart.
Blue Prices show stock on hand. More . . .
  Cat.# Price
Controller 9500-06 $ 977
(One required per desiccator)
9500-02A $ 684

File Type File Name Publication Date
White Paper (PDF) On-Site Nitrogen Generation: Cheaper, Easier, More Reliable
Learn how on-site nitrogen generation saves money by not having to order canisters of inert gas for desiccators, glove boxes and analytical instruments. You can make your own purified nitrogen from compressed air using a sophisticated membrane module (find out how it works!).
Tech Resource (PDF) Which Nitrogen Control System?
A comparative guide to Terra’s control system features and benefits.
Manual (PDF) Desiccator Cabinets and RH Controllers: Doc. # 1800-40
This manual provides installation and operating instructions for the following Terra desiccator lines: Adjust-A-Shelf, Pass-through, Wafer Box, Kitticator, Tape and Reel, Farracator and Series 100 through 400. The manual also covers the following RH Controllers: Flowmeter, Dual Purge System and NitroWatch.
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