Dimensional Calibration
esz AG's dimensional calibration laboratory is an addition to the eletrical field and dedicated to widen esz AG's scope of service towards mechanical engineering, vehicle, aircraft and aifiliated industries. Calibration engineers rely on state-of--the-art laboratory equipment at standard laboratory conditions of 20 °C ± 0,5 K.
Ideal infrastructure, laboratory architecture and air conditioning for dimensional calibration
Enhanced precision is the clear focus at esz AG's dimensional calibration laboratory, as opposed to an electronic approach towards tracing the metrological quantity "meter". To avoid virbration transmisson from surrounding technical areas the dimensional calibration laboratory's floor section is physically separated from adjacent laboratories. Aside from standard climatic laboratory conditions the dimensional calibration laboratory is pressurized to minimize the impact resulting from particulate matter. The in-house developed caliper calibration system obtained accreditation in 2005 along with related quantities: Test gauges, micrometers and portable measuring instruments.
Calibrating portable measuring instruments
All dimensional calibration in particular calipers, sliding calipers and test gauges are calibrated in compliance with VDI/VDE/DGQ/DKD 2618, page 11.1, VDI/VDE/DGQ 2618, page 9.1 respectively VDI/VDE/DGQ 2618, page 10.1. Initial to all calibration is thorough cleaning of the test object, applying cleaning solvent under a sealed laboratory hood. The calibration procedure includes visual inspection (e.g. verifying divison scale, numbers, readability et al.), basic functional testing of (if applicable) effective range, adjustability, self-locking divison scale, check marks, flow and overflow, cycle counter and lifting device.
Calibrating calipers and test gauges requires precise manual operation
Whilst micrometer calibration is processed on a designated test bed, acquiring measurement data regarding test gauges and calipers is considered a little more complex and requires evaluation of various test points, equally distributed over the test object's full range. Alongside, parallelism and flatness are subejct to determination.
Tooling Equipment Calibration
Tooling equipment, angle brackets, paint thickness gauges, durometers, clinometers, altimeters, spacer, setting jigs, etc., is calibrated by direct comparison to a primary standard related and traced to a dimensional calibration quantity for instance lenghth. This way multiple measuring task are realized at 0,1 micrometer accuracy.
Zero tolerance for exceeding tolerance limits
Flatness, as a vivid example for an elementary characertistic of any tooling equipment, e.g. to state the form tolerance of a created, flat surface (for instance by milling or grinding), turns into a measurable quantity down to the bare minimum. The tolerance limits are defined as two virtual area in parallel to an ideally generated area. Calibration is performed on a test plate or two well defined points (e.g. calipers) by determing the flatness or rectangle deviation using a height gauge.
Gauge Block Calibration
High accuracy gauge block calibration is performed applying a gauge block comparator according to VDI/VDE/DGQ 2618, page 3.1.. Substitution measurement enables gauge block calibration scaling one's own primary standards at ranges of 0,5 mm up tp 100 mm. Measurement data is processed electronically, semi-automatically, transmitted an evaluated at a PC-client. Subject to determination are mean size deviation in relation to nominal size and upper respectively lower mean size deviation fo and fu.
Gauge Blocks - setting the standard in dimensional calibration
Gauge block calibration requirements in terms of climatic laboratory conditions are extremely high. An 0,5 K deviation or exceeding tolerance class 2 according to DIN ISO 3650 table 4 will unevidable result in an aborted calibration attempt. The plane-table is equipped with wear-resistant steel to allow an almost friction less lateral adjustment. Measurement is utilized by taking 5 test points from a primary standard and its corresponding device under test. Data is acquired applying two inductive test sensors. Lifting the sensors inbetween lateral adjustments is realized, deploying an electro-pneumatic extractor including a caliper siphon to extract and move calipers without physically touching i.e. altering the climatic state.
Calibrating length standards
Calibrating threads, adjustments rings, et al. is of similar complexity: tactile measurements are taken deploying ruby, ball guided sensors. Handling requires a great deal of sensitivity along excellent precision mechanical skills. Stating a test object's condition "good" or "poor" is considered inadequate in modern day quality management. Hence calibration quantities like incline, diameter, roundness or form deviation are increasingly important in order to evaluate and document test and measurement equipment's condition.
Automated test procedures for most accurate results
Utilizing a measuring force operated and joystick activated measuring slide including a progressive deflection characteristic, atomated contact recognition, automated recognition of external, internal gauging and computer based reversal point identification, clearly simplify the handling procedure, as opposed to conventional procedures, and is responsable for most accurate results. Significantly small measurement unscertainties are realized by aerostatic slide bars for all mounted measuring slides, flexible beds of the measurement sleeve including elecronical controled measuring force and auto touch. Thus, subjective impacts and accidental test object collision are kept at a minimum.
esz AG's field dimensional calibration is specialized in calibration of test and measurement equipment as follows:
calipers / micrometers / indicating caliper / parallel gauge blocks / test pins / cylindrical plug gauges / thread plug gauges / adjustment rings / angle brackets / clinometer / spacer / threads
