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Calibration and Preventative Maintenance Procedures

 Calibration and Preventative Maintenance

Calibration: A comparison of two instruments or measuring devices one of which is a standard of known accuracy (traceable to national standards) to detect, correlate, report or eliminate by adjustment, any discrepancy in accuracy of the instrument measuring device being compared to the standard.


Calibration Programs Required by Regulatory Authorities

“Automatic, mechanical, or electronic equipment or other types of equipment, including computers, or related systems that will perform a function satisfactorily, may be used in the industries like power plant, oil & gas, cement, manufacture, processing, packing etc. If such equipment is so used, it shall be routinely calibrated, inspected, or checked according to a written program designed to assure proper performance.

Maintenance at appropriate intervals to prevent malfunction & shall be “preventative” not “reactive” maintenance.

Calibration requirements for Laboratory Instruments

Specific Directions

Schedules

Limits of accuracy & precision

Remedial Actions

Systems to prevent usage of instruments failing calibration

• “Control, weighing, measuring, monitoring and test equipment that is critical for assuring the quality of intermediates or APIs should be calibrated according to written procedures and an established schedule.


Each Manufacturing / Process Area:

Written calibration procedures that use traceable calibration standards or calibration equipment.

Preventive maintenance procedures and / or referenced manuals

Qualified individuals (having the appropriate education, training, background and experience) responsible for calibrating & maintaining instrumentation

Second person check of all calibration and maintenance

Qualified individuals responsible for monitoring the calibration and maintenance program.

Ensure the calibration program and procedures are reviewed and approved by Quality

Instrument / Equipment Master List

System for identification of all Master equipment related to instrumentation in a manufacturing/process area or laboratory

Include instrumentation details (serial number, model number & location)

If automation components are tracked separately through the configuration management then it is not necessary to include (must verify)

Procedures must exist that identify the calibration and maintenance requirements for each instrumentation / equipment on the master list

Retired Equipment

Records pertaining to retired / obsolete equipment must be kept according to company’s records retention procedures

Records should include date the unit was retired, person responsible and the reason for retirement / discard

Instrument Identification & Calibration Status

Each instrument given a unique identifier

Instrumentation details associated with this number must be documented and available (e.g. serial number, model number, location, etc.)

Each instrument should be labeled with the unique identifier

Calibration status of each instrument , the date of calibration, the next calibration date and the identification of person performing calibration should be readily available

Appropriate systems to document calibration status include calibration logs, MAXIMO, and calibration stickers

System must be in place to prevent use of an instrument that is not qualified, unusable due to damage or malfunction, or has exceeded its established calibration interval

System must be in place that identifies instruments that do not require calibration to be performed beyond the original or factory calibration to distinguish from those instruments that do require scheduled calibrations

⇒Documentation required for excluding equipment


Traceability of Standards / Calibration Equipment

Calibration reference standards / calibration equipment shall be traceable to national standards and be accompanied by certificates of traceability / analysis

If recognized standards are not available, an independent reproducible standard may be used

The calibration tolerance of a given standard should be as tight or tighter than the tolerance of the instrument to be calibrated

A procedure must be in place to ensure tracking and monitoring of standard’s expiration date and re-calibration / re-certification requirements

Re-calibration records must be retained

Instrument Calibration Tolerances

Instrument calibration tolerance limits should be established so problems are identified and corrected in a timely manner


When assigning tolerances, considerations given to:


Capability of the instrument being calibrated (what the manufacturer/OEM claims the instrument can achieve).

Parameters at which the instrument operates (ex: if testing accuracy of + 0.5% is required, the instrument calibration tolerances should be <0.5%)

Work environment – environmental conditions can affect the performance of the instrumentation

Practice of using “Alert” & “Action” levels


“Alert” Tolerance (“Adjustment Limit”)


Related to instrument performance

Level at which the instrument is adjusted back into range

Not required – an industry “best practice”

“Action” Tolerance (“Calibration Limit” or “Out-of-Tolerance”)


Tied to process performance

Level at which the potential for product impact exists

Possible atypical investigation or reporting is required

Deviations beyond “Alert” level but not at “Action” level would not require investigation – May require adjustment, changes to PMs


Setting of “Alert” and “Action” levels should be described in SOPs, be defendable and have Quality review and approval


Calibration and Maintenance Frequencies

May be determined for individual instruments or groups of instruments (similarity of construction, reliability, and stability)


Considerations when determining calibration frequency:


Accuracy of the measurement / instrument range

Consequences of incorrect value caused by out of calibration

Extent & criticality of use of the instrument & tendency to wear and drift

The manufacturer’s/OEM’s recommendations

Environmental & physical conditions (temperature, humidity, vibration)

Previous calibration records, history of calibration problems & repair history

Frequency of calibration checks prior to use or in-between intervals

Redundant / back-up systems (provides secondary source of information available from other calibrated primary instruments)

Results of Qualification studies

Process requirements

Availability of built-in / automatic calibration checks

Changes to frequency must be approved per change control SOPs


References to specific instrument procedures listed in compendium (USP, BP or EP) for calibration tests for specific laboratory instruments


Calibration time “windows” should be established around calibration due dates


Policy for Calibration and Maintenance Intervals & Schedules Include:

Extending Intervals

Reducing Intervals

Maximum Intervals

Maintenance Requirements

Manufacturer’s/OEM’s recommendations

Parts that wear: gaskets, seals & bearings

Parts requiring periodic replacement: filters, belts & fluids

Parts requiring periodic inspection and cleaning

Parts requiring periodic adjustments, tightening and lubrication

Calibration and Maintenance Procedures

Shall include specific directions and limits for accuracy & precision

Shall include guidance for remedial action when accuracy & precision limits are not met

Normally provided in the manufacturer’s/OEM’s manuals

Some compendial requirements exist for some specific laboratory instrumentation

Performance checks (e.g. system suitability, daily balance performance checks) are NOT suitable substitutes for regularly scheduled calibrations

Each calibration & maintenance procedure should include the following:


Identification of department responsible to perform the calibration or maintenance

Step-by-step calibration instructions, reference to appropriate calibration procedures or instrument manuals

Methods for preventive maintenance or reference to appropriate instrumentation manuals

Calibration equipment used in the calibration (e.g. spectroscopy filters, voltmeters, digital thermometers, etc)

Calibration parameter and tolerance ( ± )

Each calibration & maintenance procedure should include the following:


Required environmental controls or conditions, where appropriate

Provisions for adjustments, if needed

Requirement for recording actual measurements before (“as found”) and after adjustment or preventive maintenance (“as left”)

Actions to be taken if instrumentation cannot be calibrated (e.g. contact appropriate service people, label and remove from service)

A step to record all calibration & maintenance activities.

Note : “as found” recordings are not required where routine performance checks are available to provide evidence indicating instrument is operating properly and is suitable for use.


Use of Contractors / Vendor Service Personnel

Must have a procedure for approving contractor activities

Contractors must have appropriate training / qualification

Responsible to review & approve the contractors calibration and maintenance procedures.

Responsible to perform actions or steps not part of the contractors procedures.

Calibration & Maintenance Records

All calibration records must be retained per document retention procedures

Should include “as found” measurements, results of adjustments (“as left”) and appropriate review & approval of all results

Tolerance or limit for each calibration point

Identification of standard or test instrument used

Identification of persons performing the work and checking the results with dates

Review must ensure the approved activities have been completed and all results have passed the established acceptance criteria

Periodic review of historic calibration & maintenance data to evaluate appropriateness of established frequencies

Procedures for Out-Of-Tolerance Calibration Results

Actions required when critical instrument found outside of established instrument calibration limits (“Action Limit”,Out-Of-Tolerance, OOT):


Critical Instrumentation: Any instrument employed in the production of bulk pharmaceutical chemicals, drug or biologics product that controls and/or is used to measure a parameter that affects the validation state of the product (Critical Process Parameters) and any other quality parameter designated as such. Also includes laboratory instrumentation used to measure conformance to component and/or product specifications.


Instrument Mechanic/Technician:

Immediate review of calibration data to verify validity of OOT

Notification to supervisor or responsible person

Instrument Services :

Corrective Action to the instrument ASAP (repair, re-calibration, replacement or removal from service)


Investigation and documentation into root cause of OOT


Historical review of instrument performance & factors relevant to setting calibration frequency

Corrective Actions to prevent recurrence

Re-calibration after maintenance or repair

OOT Notification issued to instrument owner (after results validated)


OOT Notification should include current calibration data, magnitude of OOT error, and date of last successful calibration


Instrument Owner :

Evaluate impact of OOT on product quality.


Impact evaluation based on SOP which is approved by Quality and defines how / when Quality will be notified.


Ex. of OOT with impact on quality:


Instruments used in acceptance / rejection of materials and product

Control / monitoring of critical process parameters

Process controls affecting the final product quality or yield

Instruments required by regulation (e.g. gauges, RH monitors, etc.)

Calibration reference standards

Needs complete understanding of the process requirements for the parameter measured by the OOT instrument


Evaluate magnitude of error in the “As Found” OOT vs. process requirements to determine quality impact


Ex. of OOT with no impact on quality:


⇒A temperature transmitter is reading 0.2 Deg C low and is OOT for that instrument. There is no potential for quality impact if:


– Process requires temperature reading accuracy of +/- 1 DegC –


– Measures a range / CPP with max. 85 Deg C and process normally runs at 75 Deg C.


Decisions regarding impact on quality must be documented, approved by Quality and documentation retained

OOT events should be tracked and trended to identify problem instruments

Historical information on OOT events should be readily retrievable

Change Control Management

Changes to calibration tolerances, frequency, procedures, addition to / deletion from calibration program, changes in location and different replacement parts should be documented in a change control program

May also require re-calibration, re-execution / revision of instrument’s Installation Qualification (IQ), Operational Qualification (OQ) or Performance Qualification (PQ)

Update of qualification records: drawings, parts list, etc.

Appropriate review and approval by responsible departments and Quality

FLOWCHART :



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