Standard Operating Procedure for Calibrating Pressure Sensors in Nebulizer Systems

1) Purpose

The purpose of this SOP is to define a standardized procedure for calibrating pressure sensors used in nebulizer systems to ensure accurate and consistent pressure measurement during operation.

2) Scope

This SOP applies to all pressure sensors installed in nebulizer production equipment, including solution preparation vessels, filling machines, and assembly lines.

3) Responsibilities

Operators: Assist with sensor calibration activities and ensure equipment is prepared for calibration.
Maintenance Team: Perform the calibration of pressure sensors as per this SOP.
Quality Assurance (QA): Verify calibration results and approve calibration records.

4) Procedure

4.1 Pre-Calibration Checks

• Verify that the calibration equipment, such as pressure calibrators or manometers, is functional and within its calibration validity.
• Inspect the pressure sensor for physical damage or contamination that may affect calibration.
• Ensure the system or equipment to which the sensor is attached is clean and prepared for calibration.
• Document the pressure sensor’s details, including model number, serial number, and location, in the Calibration Log.

4.2 Calibration Procedure

• Connect the pressure calibrator to the pressure sensor using appropriate fittings and ensure a leak-free connection.
• Set the calibrator to zero and confirm the sensor reads zero pressure.
• Apply known pressure values incrementally (e.g., 10%, 25%, 50%, 75%, 100% of the sensor range) and record the sensor’s readings at each step.
• Repeat the process in reverse order to check for hysteresis or inconsistencies.
• Compare the sensor’s readings with the calibrator’s values and calculate any deviations.
• If the deviation exceeds the acceptable range (as specified in the equipment manual), adjust the sensor calibration settings using the manufacturer’s software or hardware interface.

4.3 Post-Calibration Verification

• After calibration, repeat the pressure application and recording process to verify that the sensor is now within acceptable tolerance limits.
• Document the pre- and post-calibration readings in the Pressure Sensor Calibration Report.
• Label the sensor with the calibration date, next due date, and the initials of the person who performed the calibration.

4.4 Frequency of Calibration

• Routine Calibration: Quarterly or as per the manufacturer’s recommendation.
• Post-Maintenance Calibration: After repairs or replacement of sensor components.
• Annual Calibration: Comprehensive calibration performed by a certified external agency.

4.5 Handling Calibration Failures

• In the event of calibration failure, isolate the affected equipment and inform the QA team.
• Document the issue in the Calibration Failure Report and implement corrective actions.
• Do not use the sensor until it has been recalibrated successfully.

5) Abbreviations

• QA: Quality Assurance
• MSDS: Material Safety Data Sheet

6) Documents

The following documents should be maintained:

• Pressure Sensor Calibration Log
• Pressure Sensor Calibration Report
• Calibration Failure Report

7) References

Relevant regulatory guidelines and references include:

• ISO 13485: Medical Devices Quality Management Systems
• Good Manufacturing Practices (GMP) Guidelines
• Equipment Manufacturer’s Manual

8) SOP Version

Version: 1.0

Annexure

Annexure Title: Pressure Sensor Calibration Log

Date	Sensor ID	Equipment ID	Calibration Range	Performed By	Remarks
DD/MM/YYYY	Sensor Identifier	Equipment Identifier	Pressure Range	Technician Name	Details of calibration

Annexure Title: Pressure Sensor Calibration Report

Date	Sensor ID	Applied Pressure	Sensor Reading	Deviation	Remarks
DD/MM/YYYY	Sensor Identifier	Pressure Applied (kPa)	Reading (kPa)	Deviation (%)	Details

Annexure Title: Calibration Failure Report

Date	Sensor ID	Issue Identified	Corrective Action	Performed By	QA Approval
DD/MM/YYYY	Sensor Identifier	Description of Issue	Corrective Steps	Technician Name	QA Name