Walk-in stability chambers

Figure 16.2. Typical sensor placement pattern for a walk-in stability chamber.

Fig. 14.2 ESI Walk-in stability chamber with CCS Touchscreen control (Photo Courtesy of Metrics Inc.)...

Sensors are distributed equally in various areas of the stability chamber no less than 2 inches from any wall. A set of sensors should be placed near or at the temperature and/or humidity controller of the chamber, as the controller will maintain the set-point temperature and/or humidity within the chamber during normal use. For a typical walk-in chamber, a minimum of 24 thermocouples and six resistance-transmitting devices are recommended for use in the mapping study. For a benchtop or reach-in chamber, a reduced number of sensors may be used. It is important to note that regardless of the size of the chamber, the placement pattern of the sensors should be such that any potential hot or cold spots are mapped, particularly those areas near the door and comers of the chamber. Typical sensor placement patterns for a reach-in and walk-in chamber are shown in Figures 16.1 and 16.2, respectively. In these examples, the extremities of the chamber (i.e., top and bottom) have a larger number of sensors than the middle of the chamber, since these areas would have a greater probability of either hot or cold spots, due to the airflow pattern within the stability chamber. 

Figure 24 PSC062 Pharma-Safe". (A) Stability test chamber, photostability model (B) custom built walk-in unit (C) exposure equilization filter. Source. Courtesy of Weirs Gallenkarmup.

In Figure 33 is pictured Weiss Gallenkamps LSC020.STX.C (A), Light Stress Chamber (39). This unit has a metal halide lamp as its sources for irradiation. This option is also available in their custom-made, walk-in, drug stability rooms. 

Stability chambers can be obtained in a wide variety of sizes from commercially available small bench top reach-in chambers to large custom-designed walk-in rooms. Today the chamber manufacturer can provide high quality chambers at almost any size, for use at just about any condition. 

---