Day 31 — Temperature Calibration Fundamentals

What is the title of the Day 31 calibration infographic?

Temperature Calibration Fundamentals

What is the subtitle or main question addressed in Day 31?

What are the key principles

What learning journey series is this infographic part of?

Continuing my 90-Day Calibration Learning Journey from Beginner to Calibration Specialist 2026

What is temperature calibration defined as?

The process of comparing a temperature measuring device with a known reference standard under specified conditions to establish the relationship between indication and reference value with uncertainty

Does temperature calibration automatically mean adjustment or verification?

No

What instruments are typically shown in the temperature calibration setup example?

An IUT like a Fluke 54-II B type K thermometer

What is the VIM definition of calibration?

Operation that establishes the relationship between a measurement standard and the indication of a measuring instrument

What is a measurement result?

Value attributed to a quantity

What is a true value?

Value consistent with the definition of the quantity

How is error defined in the VIM table?

Result minus true value

What is a correction?

Value added to the indication to obtain a corrected value

How is measurement uncertainty defined?

Parameter characterizing the dispersion of values

What is a reference standard?

Realization of a measurement unit or reference value with known uncertainty

What is traceability defined as?

Property of a result related to a reference through an unbroken chain of calibrations

What are the two primary calibration methods covered for temperature?

Dry-block and liquid-bath calibration

What is a dry-block calibrator?

A temperature-controlled metal block or insert with borings for probes

What are the key advantages of a dry-block calibrator?

It is convenient and portable

What parameters must be checked when using a dry-block calibrator?

Probe fit

What is a liquid-bath calibrator?

A temperature-controlled liquid medium such as water or oil

What are the advantages of a liquid-bath calibrator?

Good thermal contact and uniformity with stirring

What parameters must be checked when using a liquid-bath calibrator?

Liquid compatibility

What does calibration versus adjustment mean?

Calibration establishes the relationship between indications and reference values while adjustment changes the instrument to produce prescribed indications

Why is thermal equilibrium important in temperature calibration?

Sufficient time must be allowed for the probe and medium to stabilize according to the procedure

Why does temperature uniformity matter?

Temperature can vary across the medium so probe placement and immersion depth matter

What does traceability require in temperature calibration?

A documented chain of calibrations

What does the uncertainty principle state regarding reference instrument specifications?

Reference instrument specifications alone do not represent the complete uncertainty of a calibration

How is measurement error calculated using the specific formula in the lesson?

Error e equals indication minus reference value

How is correction calculated using the specific formula in the lesson?

Correction C equals reference value minus indication

What is the calculated error if the instrument indicates 100.4 degrees Celsius and the reference value is 100.0 degrees Celsius?

The error e equals +0.4 degrees Celsius

What is the calculated correction if the instrument indicates 100.4 degrees Celsius and the reference value is 100.0 degrees Celsius?

The correction C equals -0.4 degrees Celsius

What contributions are included in measurement uncertainty for temperature calibration?

Reference calibration uncertainty

What is the warning regarding combining uncertainty effects?

Do not automatically combine every listed effect

determine which components apply

evaluate them appropriately

What is the hierarchical chain shown for traceability in temperature calibration?

National or international standards flow to a calibration laboratory

What should be checked when evaluating a reference thermometer?

Calibration certificate

What distinction does Fluke make regarding the 1523 reference thermometer readout?

Readout performance is not equal to full probe accuracy

What is stability as a performance parameter?

How well temperature is maintained over time at a specified location or condition

What is axial uniformity?

Temperature variation along the depth of a block well

What is radial uniformity?

Temperature variation across wells or positions at a specified level

What is an immersion effect?

Difference associated with insertion depth and heat transfer along the probe stem

What is a loading effect?

Temperature change caused by inserting probes or changing the load in the block

What is hysteresis in temperature calibrators?

Dependence of indicated temperature on the previous thermal state or direction of approach

What model example is given for stability and axial uniformity in the infographic?

Fluke 9142 with stability of plus or minus 0.01 degrees Celsius and axial uniformity of plus or minus 0.05 degrees Celsius at 40 mm

What must a technician check before starting a temperature calibration according to practical takeaways?

Reference thermometer

What is the technical question in the Your Turn Calibration Challenge?

If the instrument indicates 100.4 degrees Celsius and the reference value is 100.0 degrees Celsius

What is the answer to the technical question in the challenge?

The error is +0.4 degrees Celsius and the correction is -0.4 degrees Celsius

What is the witty question in the Your Turn Calibration Challenge?

Why shouldn't a technician trust a temperature reading just because it looks stable?

What is the answer or reasoning for the witty temperature reading question?

Because stability alone does not guarantee accuracy

What is the practical question in the Your Turn Calibration Challenge?

If two probes show different readings in a dry block

What should be investigated when two probes show different readings in a dry block?

Investigate probe fit

What standards and references are cited at the bottom of the infographic?

VIM BIPM JCGM