Ensures a constant positive pressure inside desiccators and other enclosures to block contamination and moisture inflow
Automatically activates high-flow purge when doors are opened to ensure fast, effective purge of particles and moisture
Operates in tandem with NitroWatch® to maintain any desired sub-ambient moisture level (down to 0% RH)
Guards against pressure damage to desiccator doors and seals
Door switches are highly reliable—rated for over 10 million operations
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.
Dual Purge System Offers Variable-Purge Security
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.
Safety Alarms Ensure Worry-Free Operation
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!
NitroWatch™ Controller Expands Capabilities
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.
The NitroWatch™ is available in two configurations:
Smart® NitroWatch™ includes temperature sensing and built-in data logging (downloadable to a USB flash drive).
Standard NitroWatch™ does not include temperature sensing or data logging.
Specifications
Dimensions: 12"W x 11.25"D x 7"H (305 mm x 286 mm x 178 mm)
Weight: 16 lbs. (7258 g.)
Flowmeter: 0-20 SCFH
Line Pressure Gauge: 0-60 psi
Chamber Sensor: 0 - 0.4" WG (factory set at 0.02" WG)
Smart humidity controller provides automatic setpoint control and data logging
Works in tandem with Terra's Dual Purge to maintain sub-ambient RH set-point down to 0% RH
Connects to a single sensor to monitor, control, and log data inside desiccator cabinet or glovebox
Logs RH, temp, door open/close, purge on/off, and sensor removal/ attachment (door open/close logging not available on IsoDry Cabinets)
Data file is .CSV with ~4MB or 113,000 readings; intervals of 1 SEC, 10 SEC, 1 MIN, 5 MIN, or 1 HR
Terra Universal's Smart® IsoDry® Nitro-Watch™ senses and displays the relative humidity level (from ambient to 0% RH) inside a desiccator or glove box within ±1.5% RH. It operates in tandem with Terra's Dual Purge™ System to precisely and automatically control the flow of nitrogen into a desiccator, glove box, or similar enclosure, and maintains a preset humidity level, no matter how operating conditions may change.
Programmable logic gives user complete control over warning alarms and other system functions.
Automatically controls Dual Purge™ System with high/low flow purges to maintain any relative humidity from 0% RH to room ambient.
Data Logging: Unlike the standard NitroWatch™, the Smart® NitroWatch™ also measures temperature and logs data. This system logs RH, temp, door open/close, purge on/off, and sensor removal/attachment. The system can log months of data depending on the logging interval selected, all of which can be downloaded to a USB flash drive. Plug in USB flash drive and system transfers data in .CSV format. No software required.
Application Note: The NitroWatch sensor provides an exact %RH reading in one chamber only. If multiple RB valves are installed and doors are frequently opened, this reading may not be representative of all chambers. For precise chamber-by-chamber monitoring and control in a desiccator cabinet, select Terra's NitroPlex system. For gloveboxes that require greater accuracy and control, Terra's DewWatch™ measures moisture volumes down to 0.5 PPM. Door open/close data logging not available on IsoDry systems.
Automatically controls Dual Purge™ System to maintain the desired low relative humidity level (2%RH to ambient) in a glove box 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, causes unnecessary costs!
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, simply because no adequate controller has been available.
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.
Additional Savings Through Reduced Nitrogen Waste
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 can be placed nearly anywhere inside a sealed enclosure without interfering with shelves, doors, process equipment, or stored materials. This sensor features miniaturized components that provide better than 3%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.
Specifications
Dimensions: 11"W x 6.25"D x 3"H (279 mm x 159 mm x 76 mm)
Weight: 8 lbs. (3629 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: ±.04%RH/°C
Measuring Range: 0-100%RH
Accuracy (at 20°C): ± 3%RH
Housing Material: 304 Stainless Steel
Calibration: None required.
Products Tailored to Your Cleanroom Environment
Provide Terra with your desired ISO Grade™ design. We will tailor the product to meet your criteria and certify it with a report appended to your invoice. Certificate includes all the necessary information to streamline audits and facility compliance.
Dual Purge™ and NitroWatch™ Work Together to Fully Automate RH Control
Terra's Dual Purge™ and NitroWatch™ operate in tandem to precisely and automatically control the flow of nitrogen and maintain a preset humidity level (from ambient to 0% ± 1.5% RH), no matter how operating conditions may change.
Data Logging with 113,000 Readings at User Defined Intervals
Terra's Smart® IsoDry® Nitro-Watch™ logs RH, temp, door open/close, purge on/off, and sensor removal/attachment. The max data file size is roughly 4 MB or 113,000 readings. This is approximately 32 hours of data when logging at 1 second intervals, 2 weeks at 10 second intervals, 6 weeks at 30 second intervals, or 12 weeks at 1 minute intervals. When the system reaches the 4MB limit, data begins to wrap, overwriting oldest data with new.
Dual Purge™ System Diagram
The Dual Purge™ is a variable gas-purge system that switches between "high-flow" and "low-flow" to efficiently and effectively remove and block out moisture and contaminants. Without NitroWatch™, Dual Purge™ does not sense or display RH%. It uses magnetic door sensors to initiate high-flow. When a door is opened or when pressure drops, high-flow activates for a user-specified interval before switching back to an adjustable low-flow setting to conserve nitrogen. With all doors closed, the system maintains an economical "low-flow" to maintain constant positive pressure.
Dual Purge™ and Nitrowatch™ System Diagram
The NitroWatch module connects to a humidity sensor inside the desiccator cabinet and activates the Dual Purge to automatically maintain sub-ambient RH down to 0% RH. When the RH set-point is reached, the system reverts from high-flow to low-flow nitrogen gas to maintain the set-point and conserve nitrogen. When a door is opened, or when the RH climbs above set-point, the system re-activates high-flow to accelerate moisture removal.
Plug & Play Data Logging
Plug in a USB flash drive to your Smart® IsoDry® Nitro-Watch™ to transfer data in .CSV format. No software required.
Highest Standards For Desiccators and Electronic Components
Terra’s desiccator cabinets and RH control systems are designed and built to the highest standards required by defense and semiconductor industries for long-term reliability and protection against damage, injuries, and electrical hazards.
Catalog of CE-Marked Products
Terra offers over 1,700 CE-marked products configured for international voltage requirements
On a tight schedule?Choose FasTrak 24/7 Priority Service to help meet your critical schedule for Terra-manufactured products, either before or after your order is placed.*
FasTrak 24/7 provides a 24/7 commitment to meet the shipping date YOU specify, regardless of quoted lead times.
FasTrak 24/7 assigns a dedicated production team plus a dedicated senior expeditor working three shifts to meet your delivery specification.
FasTrak 24/7 guarantees* to meet the agreed-to specified ship date.
Call for pricing. FasTrak service fees cover costs of additional services only, without additional profit.
* Terra's FasTrak services limited guarantee: to ship on the ESD or date specified OR to refund up to 100% of FasTrak charges. This guarantee covers no direct, special, consequential or other damages and is strictly limited to up to 100% of the amount paid for FasTrak service. When a specified ship date is missed due to factors outside Terra's control (vendor performance, deliveries by shipping companies, etc.) and random factors such as accidents, the credit of up to 100% of the FasTrak 24/7 may not apply. FasTrak service requested after order placement will be quoted and accepted based on available time remaining before required ship date.
