SOP on Operation of Stability Chambers

SOP on Operation of Stability Chambers


  • To lay down a procedure for the operation of stability chambers.


  • This SOP is applicable to quality control laboratory


  • Chemist or above of QC Laboratory.


  • Head – Quality Control.


Following points shall be checked before starting the stability chamber :

stability chamber

  • Stability chamber shall be 2 feet away from the wall for better air circulation and for walk-in-chamber condensing unit shall be 2 feet away from wall.
  • Level of water in the boiler tank shall be upto middle of the float switch.
  • Water used for stability chamber shall be soft water.
  • Boiler heater pin shall be connected to the boiler heater.
  • The environmental temperature shall be below 30° C.
  • Single phase UPS supply shall be given to PLC and complete input and output supply shall be check.

If above points found OK, put ON the mains on the control panel and check the  Following :

  •  Display on temperature controller shall be ON.
  • Display on Humidity Controller shall be ON.
  • Display on safety controller shall be ON.
  • Display on printer interfacing unit shall be ON.
  • Inside chamber motor shall be ON.
  • Display on the scanner shall be ON.
  • Display on the PLC shall be ON.

a)  Now set the required temperature on the temperature controller by  pressing the increment and decrement key, which will display the set point .Now the bottom display will show the set temperature and the top display will show  the actual temperature.

b)  Now set the humidity on the humidity controller similarly as the above as temperature controller.

c)  Set the safety controller with the same set temperature as that set temperature controller.

  • Also set the required alarm band and initial time the safety controller  will cut off the mains contractor in case of overshoot or undershoot of the temperature above the alarm band.
  • In case when the safety controller trips, Safety shall be reset to restart the chamber.
  • Set the print time intervals on the printer interface unit and connect the computer for data communication
  • Now Press Z1 button on the PLC to start the mains contractor of the chamber   nd check the Main Contractor, Air Heater and Refrigerator condensor. These shall be “ON”.
  • Z3 is used for Alarm acknowledgement  (To turn OFF the Hooter in case  of any alarm).
  • Z4 is used to Reset any alarm text.
  • Daily printout of the temperature / RH shall be taken with the help of computer. And manual monitoring of Temperature and RH shall be done as per Annexure A09.
  • Door of the chamber shall be open for less than 1 minute at a time and for very necessary work it can be open for maximum 5 minutes more than that shall not be allowed.
  • Door of the chamber shall remain locked. These shall be opened only at the time of withdrawn and charging of samples.
  • Stand-by  humidity system and refrigeration unit shall not be start if regular  system working properly.
  • Stand-by  humidity system and refrigeration unit shall be switch ON once in 15 days for 24 hours.
  • Incase of failure of regular system Stand-By shall be started.
  • If there is found any fault at any point then inform to Engineering department as per Annexure No. A02.

For Other Pharma Related Post and Updates Click Here 

List of Annexure / Formats :

  • Not Applicable.

References (if any):

Reason for Revision:

  • Not Applicable due to new SOP


  • QC        :   Quality Control
  • SOP      :  Standard Operating Procedure
  • PLC       :  Programmable Logic Controller
  • RH         :  Relative Humidity

For more Pharma posts and updates click Here