SOP For Operation, Maintenance And Calibration Of Ultrasonic Water Bath

The purpose of this Standard Operating Procedure (SOP) is to lay down the procedure for Operation, maintenance and Calibration of Ultrasonic Water Bath.

      1. Fill the Water bath with water up to height of minimum 7cm from bottom of tank. Whenever the Ultrasonic Water Bath is required with specific temperature then heater to be kept “ON”.
      1. Ensure that there is no leakage of water from water bath.
      1. Do not put any heavy objects on the bottom of the tank as it can damage the transducers. Always use tray supplied with ultrasonic bath.
      1. Ensure that liquid does not splash on the controls and switches.
  • Basic Operation :Connect the Ultrasonic Water Bath to the main power supply with the connecting plug the cleaner into grounded outlet after power on the temperature displays the actual environment temperature time and temperature default as the last setting ones.( 3 minutes default time for initial use temperature display 0°C)Press + Button adjustable for timer working time increase 1 minute hold the key the time raised by 10 minutes continuous in the contrary.Press – Button adjustable for timer working time reduce 1 minute hold the key the reduced by 10 minutes continuous the cleaning stops when the counts down 00:00.Press Button for heating key for temperature setting with the range 0°C-80°C.Press + Button adjustable for heating a time temperature will rise 1°C holding the key temperature will rise continuously with 10°C in the contrary.Press – Button temperature reduce 1°C holding the key temperature reduced continuously with 10°C usually the best results are with 40°C-60°C.When setting the temperature if the setting temperature exceed the environment temperature Press button heating key the heating working and indicator light up below the environment temperature heating can’t start and the indicator light turn off.Heating won’t shut off automatically when the environment temperature below the setting press Button heating key in to stop heating (heating can’t stop if you don’t press Button heating key).After time and temperature setting press Button heating key en press any other keys Degas,Soft, Normal Machine start to work indicator light up if need to stop heating or ultrasonic press corresponding key again then corresponding indicator lights turn off.Machine stop working after 8hours working time (power saving mode) in this made machine restored to the standby state once you press any key.Three ultrasonic working mode:Degas mode: Press Degas Button intermittent operation of ultrasonic power for rapid removal of entrained air from liquids ultrasonic work 6 seconds and stop 2 seconds same cycle to be proceed & press Degas key again to stop it.Normal mode: Press Normal Button to start the normal faction strong ultrasonic power with large current press again to stop it.Soft mode: Press Soft Button to start soft function continuous slight variation of ultrasonic frequency to eliminate hot spots dead zones and standing waves press again to stop it. During working you will hear the “sizzling“ voice that means the cleaner running properly.
  • MAINTENANCE  : Ensure system is off and disconnect the power cable from the main socket before cleaning.Clean the water bath and replace the water on daily basis or as and when the water gets turbid.

            Calibration Frequency: Yearly

  • Carry out the Calibration of temperature indicator controller with sensor and time by an approved external party.

SOP on Laminar Air flow (LAF) – Operation, Cleaning and Qualification

LAF : Laminar Air Flow –  Airflow which is linear and positive up to working surfaces and thus prevents contamination of surrounding viable/ non viable particulate matter in aseptic handling. The Operation, Cleaning, Maintenance and Qualification of Laminar Air Flow (LAF) shall discussed in below SOP.

Laminar Air flow (LAF) – Operation, Cleaning and Qualification


  • To lay down the procedure for the operation, cleaning, maintenance and qualification of the Laminar Air Flow.


  • This Standard Operating Procedure is applicable at Microbiology section / Sterile Area where Laminar Air Flow (LAF) installed.
  • Definition of Terms :
    • Standard Operating Procedure (SOP): A written authorized procedure, which gives instructions for performing operations.
    • LAF: Laminar Air Flow: Airflow which is linear and positive up to working surfaces and thus prevents contamination of surrounding viable/ non viable particulate matter in aseptic handling.

Procedure (Laminar Air Flow – LAF):

  • Cleaning of  Laminar Air Flow (LAF)
    • First of all, Turn OFF the switch of the Air Flow and UV of LAF unit (if ON).
    • Then clean properly the working chamber from ceiling, followed by side glass and then the platform of the chamber with 70% IPA.
    • After that spray 70% IPA and switch off the visible light and then switch ON the UV light till to start the next operation.
    • Finally Routine culture handling shall perform at the end of the Sample testing only.
  • Laminar Air Flow Operation (LAF-Operation)
    • Switch ON the mains.
    • Ensure that the manometer is showing Zero reading before starting.
    • Turn the switch of the Air Flow to ON position. Ensure that the differential pressure is within the limit of 8 to 15 mm of water and record the observation in Annexure-2.
    • Turn the switch of the UV lights to ON position.
    • After 30 minutes switch OFF the UV and switch ON the Visible light. Enter the burning hour details of UV in Annexure-2.
    • Now perform the activities.

                Note:   Replace the UV Light after 999 Burning hrs.

  • Pre-Filter Cleaning of Laminar Air Flow (LAF) :
    • First of all, Switch ‘OFF’ the mains of LAF, loosen the bolts properly and take out the Prefilter slowly, without any jerks from the LAF.
    • Then Shift the filter to wash area outside microbiology analysis room where cleaning is to be done.
    • Ensure the left out opening of the Prefilter on the LAF unit shall covered with butter paper in order to prevent dust as well as the outside air moving inside the LAF unit.
    • First de-dust the filter properly with the help of dry, oil free compressed air. The compressed air shall be forced properly to prefilter of LAF otherwise it will damage the filter.
    • After dedusting, clean the prefilter properly 2 -3 times with Purified water. Allow all the water to drain completely after water cleaning.
    • Then dry the prefilter after proper draining in a clean dry environment free from the dust; otherwise the chances of contamination in the sterile environment may arise or it may decrease the efficiency of the prefilter. Do not dry the prefilter in an open environment.
    • Spray 70% IPA solution filtered through 0.45 m filter and mop SS attachment of the prefilter properly before transferring inside the microbiology analysis area.
    • Affix the cleaned prefilter properly in appropriate place by removing the butter paper cover and tighten the bolts properly.
    • Check the Differential Pressure in Laminar Air Flow (LAF) :
    • Then Place the prefilter at its position. Switch on the Laminar Air Flow (LAF) unit. Check the differential pressure is in between 8 to 15 mm of water gauge.
    • If pressure reading on manometer is not achieved, put a status label ‘Under Maintenance’ & intimate the Maintenance Department for necessary action.
    • Prefilter of the Laminar Air Flow (LAF) benches shall clean once in three months In order to retain the efficiency of the HEPA filter and proper working of LAF.
    • After the Prefilter is fixed, the area shall clean properly followed by fogging as per SOP of “Fumigation of Microbiology” before using the instrument as well as the area for operation.
    • Cleaning record is to maintain as per Annexure-1.
    • Clean the Pre filter at the frequency of 3 months ± 7 days.
  • Qualification of Laminar Air Flow (LAF) :
    • Frequency:
      • Once in six months ±15 days.
    • The qualification of LAF required:
      • If any failure observed during routine monitoring.
      • In case of breakdown, maintenance, preventive maintenance.
      • In case of change in installation location.
    • Procedure of LAF Qualification :
      • Following tests are performed during qualification and results are within acceptance criteria.
        • Air velocity test:
          • Ensure that air velocity of the LAF is checked using calibrated anemometer.
          • Acceptance criteria: The velocity of the laminar air should be within 90 + 20 % ft/min.
        • Particulate count test :
          • Ensure that particle count of the work station is done using a calibrated air borne particulate matter counter. 1 m3 of air sample is collected per filter.
    • Acceptance criteria:
      • ≥ 0.5µ particles: NMT 3500 particles per m3 ≥ 5.0µ  particles : 00 (Nil / Absent) particles per m3
  • HEPA Filter integrity test / HEPA Filter leak test (Laminar Air Flow – LAF):
  • Ensure that the filter integrity test of the HEPA filter done using PAO (Poly Alfa Olefin).
  • Acceptance criteria:
    • The penetration level should less than 0.01%.
    • In case of detection of rupture of fine filter, seal the rupture with soft silicone sealant.
    • Restrict the silicone sealing to not more than 3.0% of the area of the filter and not more than 3.0 sq. inch of single patch.
  • Qualification shall perform by external agency if facility not available at location.
  • After Completion of Qualification write the details and pest as per Annexure-3.

For basics of Laminar air flow Click here

Cleaning Record of Prefilter – LAF


Laminar Air Flow Operation Record

Laminar Air Flow Operation Record

Visiters also reading : 

A)       Isolation and Identification of Microorganisms

B)       Laminar Airflow (LAF) – Operation, Cleaning, and Qualification

  • References:
    • Operation Manual  of Laminar Air Flow (LAF) for Operation, Performance check, Sanitization and Qualification.
  • Annexures:
    • Annexure-1 : Cleaning Record of Prefilter
    • Annexure-2 : Laminar Air Flow operation Record.
    • Annexure-3 : Qualification Status Label