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Guide for Establishing and Maintaining a Calibration Constancy Intercomparison System for Microwave Oven Compliance Survey Instruments (FDA 88-8264)] (PDF Only)

Final03/01/1988
Quality ControlCalibration

Key Topics

Terms and concepts identified from this document

Scope & Applicability

Product Classes

1
Microwave Oven

product listed under 21 CFR 1002.61; compliance survey instruments for microwave ovens; Compliance survey instruments for microwave oven compliance; The subject of the compliance survey instruments being calibrated.; Compliance survey instruments for microwave ovens.

Stakeholders

2
Manufacturer

Entity responsible for submitting NDINs

Instrument Manufacturer

Provides specifications and recommendations for annual calibration

Regulatory Context

Regulatory Activities

2
Compliance Testing

testing performed on the production line and audit

Technical Repair Procedures Submission

Submission to CDRH for review before implementation

Document Types

4
Daily Check Record

sample documentation form for recording calibration data; record kept for every survey instrument for compliance testing; Appendix 3, record of daily instrument verification

12-Month Historical Record

record kept on the reference field instruments; Appendix 5 documentation for tracking long-term system constancy.

30-Day Instrument Comparison Log

log maintained for each instrument used in production or audit; Appendix 7, record for every instrument on production line; Log for recording polarization ellipticity readings and instrument details.

2 dB Comparison Check Record

Appendix 8, monitors calibration data constancy; Record for tracking instrument readings since last calibration.

Attributes

7
Calibration Constancy

determining whether an instrument's calibration is changing with time

Serial Number

Unique identifier for instruments and probes.

Non-conductive material

Material requirement for the probe-holding fixture to minimize field perturbations.

Standing wave magnitude

Determined by the quality and size of the anechoic environment.

Power Density

field setting of approximately 1.0 mW/cm2

Polarization Ellipticity

measurement of polarization response error

Polarization Ellipse

Checked to ensure instrument accuracy and constancy

Technical Details

Testing Methods

4
Absolute Calibration

calibration against absolute standards traceable to NBS

Polarization Ellipse Check

Checking the polarization ellipse of the LCR and compliance meters.

Polarization Response Measurement

checking for gross shifts in response indicating instrument damage

Daily Check Record

Appendix 3 record for monitoring polarization ellipticity readings.

Processes

4
Production Testing

testing programs to assure compliance with performance standards

LCR Calibration

Annual calibration of the Laboratory Compliance Reference instrument.

Calibration Constancy Intercomparison System

system used for establishing and maintaining calibration constancy

Absolute Calibration

Performed annually for LCR and periodically for other instruments

Identified Hazards

Hazards

1
Hazardous Electronic Product Radiation

safeguards against radiation exposure

Standards & References

External Standards

1
National Bureau of Standards

standards for absolute calibration traceability

Specifications

7
Instrument polarization ellipticity limit

Criteria for accepting or rejecting instrument performance based on ellipticity error.

Polarization Ellipticity Error Limit

Each instrument must meet the limit specified by the manufacturer.

2 dB limit

A/B ratio must be less than 1.59 (2 dB) since last calibration.

10 percent comparison test

Nonreference readings must be verified to be within 10 percent of each other.

Polarization Ellipticity Error

percentage error limit specified by the instrument manufacturer

10 percent limit

Constancy limit for mean readings of compliance instruments

2 dB

Maximum disagreement allowed between most and least sensitive instruments

Related CFR Sections (1)

See Also (3)

Guide for Establishing and Maintaining a Calibration Constancy Intercomparison System for Microwave Oven Compliance Survey Instruments (FDA 88-8264)] (PDF Only) | Guideline Explorer | BioRegHub