5 furnace setups, Engine Test Cells: Type K, φ0.25–1.0 mm
| Application | Typical conditions | Recommended wire |
|---|---|---|
| Engine Test Cells | Jet engine and gas turbine development testing. Hundreds of thermocouples per engine — requires consistent batch-to-batch EMF for valid cross-engine comparison. | Type K, φ0.25–1.0 mm |
| Turbine Blade Monitoring | Creep and thermal fatigue testing of turbine blades. Long-duration exposure at 1000-1200 °C in oxidising gas stream. | Type N, φ0.25–0.5 mm |
| AMS 2750 Pyrometry | Mandatory temperature uniformity surveys for aerospace heat-treatment suppliers. ±3 °C tolerance, calibrated instrumentation, documented traceability. | Type K or N, Class 1, φ0.5 mm |
| Composite Curing | Autoclave and oven curing of carbon-fibre/epoxy prepregs at 120–200 °C. Multiple vacuum-bagged thermocouples per part. | Type J or T, φ0.25–0.5 mm |
| Environmental Control | Aircraft cabin, wing anti-ice and fuel system temperature monitoring. Vibration, altitude and EMC considerations. | Type K, φ0.25–0.5 mm stranded |
-
Traceability
Every spool must carry a furnace batch number. AMS 2750 auditors will ask for MTCs dating back to installation. Our test records are archived and retrievable by furnace batch number.
-
Drift resistance
Type N is preferred for long-duration turbine testing. Its SiO₂ protection layer suppresses the chromium oxidation that causes Type K to drift above 1000 °C.
-
Homogeneity
Single-lot wire for each engine test campaign. Compositional gradients along the wire length produce EMF errors that vary with immersion depth. We test per ASTM E1350.
Frequently Asked Questions
What tolerance and traceability does AMS 2750 require?
AMS 2750 pyrometry requires ±3 °C uniformity surveys with calibrated instrumentation and documented traceability. Survey wire must be Class 1 / Special Limits with a furnace batch number, and the MTCs have to remain retrievable for the life of the installation.
Which thermocouple type is best for engine test cells?
Type K, φ0.25–1.0 mm. Hundreds of thermocouples run per engine, so consistent batch-to-batch EMF matters for valid cross-engine comparison — specify single-lot wire per test campaign.
Why is Type N preferred for turbine blade monitoring?
Blades are tested at 1000–1200 °C for long durations in an oxidising gas stream. The SiO₂ protection layer in Type N suppresses the chromium oxidation that makes Type K drift, so the reading stays valid across the test.
Which thermocouple type is used for composite curing?
Type J or T, φ0.25–0.5 mm, for autoclave and oven curing of carbon-fibre/epoxy prepregs at 120–200 °C, where several vacuum-bagged thermocouples are used per part.
Bottom line: Aerospace work turns traceability and drift resistance into hard requirements rather than preferences: single-lot wire with a furnace batch number for every test campaign, Class 1 / Special Limits tolerance for AMS 2750 surveys, and Type N wherever long exposure above 1000 °C would drift a Type K reading out of specification.