Stability Chambers – PH Series

The Darwin Chambers PH Series Stability Chambers are designed for performance specifications exceeding FDA and ICH requirements. For GMP studies, ultrasonic humidification provides excellent humidity control and avoids hot spots during mapping. Thermoelectric cooling provides more stable temperature control than equivalent refrigeration systems. All PH series chambers incorporate inherent cooling redundancy, quiet operation, simple serviceability and excellent reliability.

The PH Series from Darwin Chambers was introduced nearly 20 years ago as the first large capacity thermoelectric cooled pharmaceutical stability testing chamber. Thousands of our stability chambers are presently in use by many pharmaceutical, cosmetic, nutraceutical, medical device, therapeutic pharmaceuticals, pharmaceutical stress testing, and other research companies around the world. The advantages of these chambers for stability or shelf life testing are substantial.

We build chambers to meet very specific requirements in a wide variety of industries. The PH Series chambers are our most popular offering for good reasons. These chambers produce exacting results and we provide support for them with timely quoting, quick lead times, reliable insulation, trusted validation services, and superior product support in the future. Please do not hesitate to inquire for any further information that may not be provided on our website.



The PH03 is an undercounter stability chamber.



The PH011 is a bench top stability chamber designed to fit on 24” benchtops or stacked with optional racking.



The PH030 is a single-door stability chamber.



The PH034 is an extra wide single-door stability chamber.



The PH055 is a 2-door stability chamber.



The PH068 is a 2-door stability chamber.



The PH084 is a 3-door stability chamber.

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PH Series Features

PH Series

The PH series was introduced in 2003 as the first commercially manufactured large capacity Peltier-cooled pharmaceutical stability testing chamber. Over a thousand PH series stability chambers are presently in use by pharmaceutical, cosmetic, nutraceutical, medical device, and research companies around the world. The advantages of these chambers for stability testing include:

Cooling Redundancy

Each PH series chamber includes multiple, independent thermoelectric cooling units. The 7 year warranty on cooling components and the ability of our chambers to maintain temperature even if the chamber suffers multiple failures is unmatched by any other refrigeration-based chamber.

Superior Control

The PH series chambers control well within the specifications required by the FDA and ICH for GMP studies. The ultrasonic humidification system provides excellent humidity control and avoids hot spots seen during chamber mapping of steam boiler equipped chambers. Thermoelectric cooling and automatic switching system from cooling to heating control provide consistent results throughout the available temperature range. Standard control at the sensor in these chambers is ±0.2°C and ±0.3%RH.

Proven Controllers

Standard controllers for the PH series are manufactured by Fuji Electric and are ideal for stability testing chambers. Unlike many proprietary controllers, this controller is commercially available and proven in tens of thousands of installations. Standard functions include: autotuning, fuzzy logic, PID control, programmable alarms, calibration capability, ramp/soak, offset capability, etc. A touchscreen control interface is optional. Other controller manufacturers are also supported (Watlow, Allen Bradley etc.)

Options Available

Chart Recorder
Data Loggers
Full swinging interior glass door (034)

Simple Serviceability

Due to the omission of all refrigeration equipment on these models, refrigeration technicians are not required during chamber servicing. Refrigerated stability chambers are not only costly to service, but can require days to service properly. Nearly every component of thermoelectric-based chambers can be serviced within minutes with basic tools. For instance, the ultrasonic humidifier is capable of being removed and reinstalled in less than a minute and operates on non-hazardous 24 volts.

Reduced Energy Loads

The PH Series chambers utilize less energy than comparable stability chambers and introduce less impact upon building cooling systems. This efficiency “dual benefit” allows our chambers to be located in spaces unsuitable for other chambers. Electrical energy savings by the PH series vs. steam boiler equipped chambers can easily amount to hundreds or even thousands of dollars saved per year.

Service and Warranties

We offer 24 hour technical support throughout the lifetime of your chamber. In addition to our standard warranties, we also offer extended warranties for cooling components, parts and labor. We also provide qualifications, validations and preventive maintenance services at an additional cost. Please ask for a quote.

Quiet Operation

The PH chambers utilize quiet and highly efficient DC fans. Locating these chambers in laboratory workspaces is a viable option.

Globally Recognized

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