Calipered ware – a term of the porcelain industry
General definition of calipering
Calipering is a technique or a procedure, which represents a reference standard for previously defined dimensions and shapes. The calipering thereby embodies the physical dimensions and forms (embodiment of measurement). Calipers are used in metrology, production and assembly.
Calipers were created to allow easy checking of standard dimensions. In contrast to measuring methods, their application hardly contains any sources of error and provides a clear statement (good or reject). Calipers cannot be used to measure, as is often assumed, because checking with a gauge does not produce a numerical value. It can only compare the target state (caliper) with the actual state of the test specimen.
Porcelain with special application properties may require teaching. In the case of hospital crockery which is placed in rigid tray and compact systems, the calipering of the crockery pieces is necessary. Technical porcelain or absorbent porcelain components usually also have to undergo porcelain calipering.
Most of the time, the calipering of the porcelain items has to be done by human hands or very expensive digital scanning & sorting machines. With the help of suitable testing devices, templates, calibrations, etc., it must be manually assessed whether the porcelain item meets the defined tolerance limits and can be used for the intended application. Scholarly porcelain has a guaranteed property by its designation alone.
Calipered porcelain does not mean that the stacking capability is exactly 100% flush. Even calipered goods can and may exhibit conditional edge deformations, and this within the tolerance range which does not exclude undisturbed use properties. The calipering of the porcelain cannot 100% exclude small shrinkage and wall thickness tolerances.
Edge reinforcements for calipered porcelain
In order to reinforce the calipering of the porcelain, bowls in particular are provided with an all-round stacking rim. This not only reduces stack breakage under mechanical load, but also reduces the production-related shrinkage tolerance of the porcelain during firing in the kiln.
Purchase recommendations for calipered goods
When buying calipered porcelain, be sure to look for glazed shelves. The production of calipered porcelain with unglazed shelves is considerably cheaper, but also has considerable disadvantages in long-term use.
Define your requirements regarding accuracy or dimensional stability exactly when you buy. If in doubt, have the manufacturer guarantee these as warranted characteristics.
In addition to the existing quality assurance measures, we at Holst Porzellan can caliper our calipered goods according to customer requirements and on request.
Calipered goods by Holst Porzellan
Holst Porzellan/Germany carries calipered porcelain for many conventional systems of food distribution and food serving.
- System tableware for compact systems
- System bowls
- System plates
- Gastronorm trays GN
- Gastronorm plates GN