Calibration by Parameter
Pressure, mass, torque, volume, electrical and dimensional calibration.
Pressure gauge calibration: procedure, points and uncertainty
How a pressure gauge is actually calibrated — rising and falling series, hysteresis, the head correction people forget, and what the certificate has to tell you.
Balance and scale calibration: eccentricity, repeatability and minimum weight
What a proper weighing-instrument calibration covers beyond a few test weights — off-centre loading, repeatability at low load, and the minimum weight that decides what you may weigh at all.
Torque wrench calibration under ISO 6789:2017
The 2017 revision split the standard into two parts and changed what a conformity certificate may claim. What Part 1 and Part 2 each cover, and why a Part 1 certificate is not an uncertainty statement.
Pipette calibration by the gravimetric method, under ISO 8655
Weighing the water a pipette delivers is simple arithmetic wrapped around several corrections people skip — the Z factor, evaporation, and the difference between systematic and random error.
Multimeter calibration: what the specification actually promises
A DMM specification is a formula, not a number, and it changes with range, function and how long since the last adjustment. How to read one and what a calibration has to cover.
Dimensional calibration: calipers, micrometers and gauge blocks
Why 20 °C is written into dimensional standards, what thermal expansion does to a steel measurement, and how calipers and micrometers are actually checked.
pH meter calibration: buffers, slope and why temperature is not optional
pH is a measurement whose reference values are themselves assigned with uncertainty. What the slope and offset actually tell you about an electrode, and why a two-point calibration is the minimum.
Conductivity meter calibration and the cell constant
Conductivity calibration determines a geometric property of the cell, not an offset. What the cell constant is, why temperature compensation dominates the result, and what goes wrong at low conductivity.
Force calibration and tensile testing machine verification
ISO 376 calibrates the force proving instrument; ISO 7500-1 uses it to verify the machine. Why the two are separate, and what alignment does to a force measurement.
Hardness testing machine calibration: direct and indirect verification
Hardness is defined by its test method, so a hardness machine is verified twice — once on its components and once end-to-end on certified reference blocks.
Particle counter calibration for cleanroom classification
ISO 21501-4 sets what a light-scattering particle counter has to demonstrate. Why counting efficiency at the smallest channel is the specification that matters, and how flow rate error becomes concentration error.
Flow meter calibration: what the reading depends on besides flow
Flow meters are sensitive to the installation as much as to the fluid. Upstream straight lengths, the difference between volumetric and mass flow, and why a bench calibration can mislead.