Schupp Ceramics - PTCR Control rings Part 1/6 – Ring types. Choice. Advantages.

SCHUPP® Ceramics is your partner for high-temperature systems — The SCHUPP area at a glance.

14. March 2017 14:25

Optimised quality assurance by process temperature control rings

In this newsletter and in the next ones, we would like to give you useful advices and recommendations for using PTCR.

1. What are PTCR?

The process temperature control ring - PTCR - is a ceramic ring, which allows the recording of process heating. The PTCR receives the heat input at the selected location, independent of whether this is introduced by heat conduction, radiation or convection.

2. What types of rings are available?

A total of six different ring types are available for different temperature ranges.

Ring type*	Temperature range (from - to)
UTH	660°C - 900°C
ETH	850°C - 1100°C
LTH	970°C - 1250°C
STH	1130°C - 1400°C
MTH	1340°C - 1520°C
HTH	1450°C - 1750°C

*All ring types are alternatively also available in thinner L variant - e.g. ETL 3.5mm instead of 7mm high.

3. How do I select the most suitable ring type for my process?

The maximum temperature of your firing/sintering process should be approximately in the middle of the temperature range covered by the ring type. If the maximum temperature is within the limit range of two ring types, the selection falls according to the holding time and atmosphere, since both factors also strongly influence the shrinkage of the ring. Here we recommend to contact us.

4. What are the advantages of PTCR against e.g. a thermocouple?

Process temperature control rings record thermal conditions at the place where the workpiece is located. Various phenomena, occurring in a furnace/kiln, are taken into account, even if they cannot be sufficiently detected by thermocouples, such as heat sinks, temperature gradients, gas flows, atmospheres, holding time, furnace loading, etc. These are made visible by deviations from the expected temperature. A thermocouple merely reflects the temporal course of the temperature at a single point, without taking into account the above-mentioned influences. The recording of the actual heat input with PTCR over the entire duration of the furnace/kiln cycle is essential and ensures certainty about the homogeneity of the temperature field and the reproducibility of individual furnace/kiln cycles.

In the next issue you will read e.g.:

How do I use PTCR and what do I have to consider?
What influence does the holding time have on the shrinkage?
Can I use PTCR under any atmosphere?

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