Vernier and digital calipers
The instrument that gets picked up first: outside, inside and depth measurement on machined parts, tube, bar stock and finished work, read to the hundredth of a millimetre.
0.01 mm resolution · ranges to 600 mm
The six lines
Each line exists because a class of measurement needs it. Where a requirement falls outside these six, the honest answer is a referral to a laboratory that holds that quantity rather than a certificate stretched to cover it.
Outside micrometers and bore gauges
Where a caliper stops being honest: bearing seats, pin diameters, wall thickness and bore work read to the micrometre.
0.001 mm resolution · 25 mm spans
Click and dial torque wrenches
Assembly and maintenance where a joint is tightened to a figure instead of to feel: fasteners on plant, structures, flanged joints and wheel work.
±4 % of reading · three verification points
Precision balances and mass standards
Laboratory and production weighing: sample preparation, dosing checks, incoming inspection, and the reference weights the balance itself is checked against.
0.1 mg readability · calibrated in place
Gauge blocks and reference standards
The instruments that other instruments are measured against: block sets, setting rings and reference weights held as the shop's own standard.
Grade 0 and grade 1 · deviation per block
Dial and digital indicators with stands
Comparative measurement rather than absolute: runout, flatness, alignment and repeat setting on lathes, presses, jigs and fixtures.
0.001 mm resolution · checked over full travel
How a measurement is specified
Five steps, in this order. The order is the point: every step exists to stop an assumption being carried into the next one.
1
Application review
We start from the measurement rather than from the catalogue: the feature, its nominal value, its tolerance, and where in the process it is checked. The instrument follows from that, because resolution finer than a tenth of the tolerance is a rule and not a preference. Most wrong instruments were chosen from a range and a budget instead of from a drawing.
2
Written specification
Every measurement we specify carries four figures: the range, the resolution, the uncertainty, and the conditions the uncertainty was measured under. A specification missing any of the four will be read differently by every person who picks the instrument up.
3
Reference check before dispatch
Nothing leaves against a promise. Each instrument is checked against the standard for its quantity — gauge blocks for length, reference weights for mass, a torque transducer for torque — and the values found are the ones written down, before any adjustment.
4
Calibration and certificate
The certificate states the measured value at each point, the deviation from nominal, the uncertainty of that figure, the reference temperature, and the chain of standards behind it. Where the instrument was adjusted, both the as-found and the as-left values appear.
5
Interval, recall and record
The calibration interval is agreed from how the instrument is actually used, not from a number chosen in advance, and it is entered in a register with the due date. We hold the history so the next certificate can be read against the last one rather than on its own.
The range in numbers
6instrument lines, each with a stated purpose
5steps from application review to certificate
4figures every measurement is specified with
2017measuring and calibrating since
These figures describe the range and the process set out on this site, and nothing beyond them is claimed here. Technical values quoted anywhere on this site are typical values, measured at the reference temperature and under the conditions named with them.
Common questions
Can I order from this site?
No. Nothing is sold through these pages and no prices are published here. Instruments and calibration are supplied against a written specification and a written quotation, because the right instrument depends on the tolerance and the conditions rather than on a catalogue number.
What do you need in order to recommend an instrument?
The feature being measured, its nominal value and tolerance, the unit your drawing uses, where in the process the check happens, and the temperature range of that place. If some of that is unknown, say so; an assumption stated out loud is easier to correct than one buried in a number.
Do you calibrate instruments you did not supply?
Yes. The make and model do not change the procedure, only the points measured and the standard used. Send the instrument with its setting standard if it has one, because a span cannot be certified without the reference it is set against.
Does the certificate state an uncertainty?
Yes, per measured point, together with the deviation from nominal, the reference temperature and the chain of standards behind the figure. A certificate that states only “pass” is not a measurement result, and we do not issue one.
How long does a calibration take?
The turnaround is confirmed with the quotation rather than promised in advance, because it depends on the quantity, on whether the work is done here or at your bench, and on the soak time the instrument needs to reach reference temperature.
How often should an instrument be calibrated?
The interval follows the use: how often it is read, how rough the environment is, what a wrong reading would cost, and what the last few certificates did. We propose an interval and the reasoning for it, then adjust it against the history rather than defending the first guess.
Do you supply outside Trondheim, Norway?
Work outside the usual area is arranged case by case and is quoted with the order, including the transport case and the handling conditions the instrument needs in transit.
What happens if an instrument is found out of tolerance?
We report the as-found values first, then say what we did. That order matters: the as-found figures are what let you judge the parts measured since the last certificate. If an adjustment brings it back inside its class we record both states; if it does not, we say the instrument is beyond adjustment instead of certifying it anyway.
Ask for a specification
Send the feature, the tolerance and the conditions it is checked in, and you will get a written specification with the range, the resolution and the uncertainty stated for each measurement. There is no charge for the specification and no obligation attached to it.
Written enquiries reach us at contact@slatemetrology.online. By telephone, during business hours.