Laboratory Equipment Calibration Flashcards

Which calibration approach involves comparing an instrument directly against a reference standard of higher accuracy?

Answer: Direct comparison calibration

Direct comparison calibration places the instrument under test alongside a reference standard to assess agreement under the same conditions.

For a thermometer used in a CCIL-accredited laboratory, calibration points should ideally be chosen to:

Answer: Span the full working range of the thermometer in the intended application

Calibration points spanning the working range ensure the thermometer performs accurately across all temperatures used in practice.

What does 'out-of-tolerance' mean when found during a calibration check?

Answer: The instrument's readings fall outside the specified acceptable limits

Out-of-tolerance means the instrument's error exceeds the maximum permissible error defined in specifications or the calibration procedure.

In gravimetric calibration of volumetric glassware, which physical property of water is used to convert mass to volume?

Answer: Density

Water density at the measurement temperature is used to calculate volume from the measured mass of water dispensed or contained.

Which document type formally defines the step-by-step process a laboratory must follow when calibrating a specific instrument?

Answer: Standard operating procedure (SOP)

A Standard Operating Procedure (SOP) provides detailed, repeatable instructions for calibrating specific instruments consistently.

What is the recommended action when a piece of laboratory equipment is found out of calibration after being used for testing?

Answer: Quarantine the equipment and assess the impact on previous test results

ISO/IEC 17025 requires that nonconforming equipment be quarantined and a risk assessment conducted to determine if previously reported results are valid.

A spectrophotometer's wavelength accuracy is verified using:

Answer: Holmium oxide or didymium glass filters with known absorption peaks

Holmium oxide and didymium glass filters have well-characterized absorption peaks used as wavelength references for spectrophotometer calibration.